(sorry) I probably should have stuck with a more isomorphic example like discussions between eco-conscious cyclists and habitual motorists :-)  this  would have offered a more exact similitude, being prima facie a lifestyle/environment/resource question rather than a human rights or crimes-against-persons question.  there was an obvious overlap in my mind for idiosyncratic reasons, as I was thinking of a couple of specific older male friends of 25 years ago and more, whose reactions (on all three subjects, now that I come to think of it) were quite emotionally/tonally similar.  so the similarity in my mind was not the similarity of the issue or the topic, but the similarity of the defensive mechanisms we all (moi aussi) use to deflect unwanted information or perceived "moral judgment" from others.

what is interesting is that AGR personally, or his generation (I don't know his age so cannot say) or his educational or political demographic or whatever, has clearly internalised the idea that rape is very, very, terribly, seriously Bad -- and that therefore it is insane (or at least wildly over the top) to compare something so awful to the (relatively trivial) lifestyle question of eating meat or not.  but what I was trying to convey was the experience of discussion with older men, from a different time and generational mindset, who found it quite ridiculous to think of rape as a very, very seriously Bad Thing -- to them it was a trivial or unimportant thing, some would even doubt that it was possible or ever happened at all ("did you ever try to thread a moving needle, har har har") ... and they were very resistant to being told that it was a Bad Thing and should be taken seriously.   anyway, enough on that, it appears to be a red herring to a bull or some similarly dangerous mixed metaphor.  let's stick to bikes and cars, it's an easier parallel.

the bluster and joking and "lighten up" and har-de-har response seemed to me very consistent regardless of the issue, and that seemed kind of interesting to me.  I have had conversations with habitual car drivers who ask me why I ride a bike; and if I say it is "for my health" or "to save money" they are puzzled but accepting.  but if I say it is because I don't like the private automobile transport model, if I mention the numbers of people killed each year by motorist inattention or incompetence, then about half the time I'll get a har-de-har response about painting the score on the car fender or getting extra points for hitting a blind nun on a crosswalk, that kind of thing.  which I would call a defence mechanism against having the conscience tickled by unwanted information.  when we say we do X because it seems immoral to do Y, then how can people who do Y avoid the feeling that some moral criticism has been laid at their door?  and hence the defensiveness, as no one likes to be morally upbraided or preached at and (even implicitly) told to reform.

and yet how can agitators for social justice agitate, if not by saying that doing Y is harmful in some way and that X is a better alternative?

yes, the bike riding analogy really is far better.  one could argue similarly that vegetarianism is purely a personal decision for better health or weight loss, which is "harmless" and doesn't arouse much reaction -- other than perhaps a warning about the health risks of not eating meat :-)  but most vegans and vegetarians have motives that are both altruistic/political and personal. even a not-so-pure incidental meat consumer like me could argue that in fact, excessive meat consumption is a human rights issue and a very seriously Bad Thing, with capitals and boldface and sound effects;  because of deforestation, because of the diversion of staple grains and pulses into meat animal fodder when billions of humans go unfed every day;  because of drawdown of that most essential resource, fresh water;  because of manure lagoons and the associated pollution;  because of antibiotic misuse and the associated increased risk of pandemics and resistant bacteria... and so on and so on.  even if we were to skip the animal-rights argument that "Meat is Murder" because we kill animals to get it, a human-rights argument could be (and I think has been) put forth in this thread that argues for the immorality of excessive meat consumption because of the illness or want it inflicts on contemporary peasants and our collective posterity.

thus there is inevitably a moralistic overtone to the critique of meat consumption, and I think this is why it can, if presented seriously, arouse similar resistance and deflection mechanisms to those that have accompanied previous reform or human rights efforts.  it is different in that it is at present a secessionist movement -- a withdrawal from a perceived harmful norm, like teetotalism, rather than the imposition of a proscriptive norm, like Prohibition or bans on smoking in public places.  but as with all the social-reform efforts I mention -- and this applies from Abolitionism on up -- an argument is being made that a state of affairs that seems perfectly normal and natural and right to a majority of people, is in fact not good for the polity on pragmatic grounds, and may be immoral on Kantian grounds as well.  [now, please, just because I mentioned Abolitionism as another instance of social norm-challenging and uphill reform or justice work, don't be thinking I just said "eating meat is the same thing as owning slaves" :-)]

the cultural changes that sparked my interest (the same defensive/protective-of-status-quo response applying to different issues in different decades) are fascinating too in that they suggest the flexibility of culture as well as its tenacity.  it is possible that by the time I am near death, the immorality of meat eating may have become as necessary a social constraint for the West as it is in densely populated, overgrazed and deforested Asian bioregions no longer capable of sustaining the wheat/beef habit.  in a generation or so, depending on peak oil and climate outcomes, habitual meat-eating might be considered quaint -- or even disgusting -- reckless, or antisocial...? or it might become an even stronger, enviable marker of class and caste when fewer people can afford the habit;  in which case movies about the gilded elite might focus lovingly on plates of roast beef in the way that they now lens-caress the eye candy of expensive cars, designer clothing and fancy entertainment centres in spacious view apartments and trophy homes :-)  teenagers might hang out after the movie muttering, "Wow man, did you see the size of that charbroiled steak?  I'd do just about anything to eat one of those, dood."

when you've lived long enough to see conventional social norms alter visibly, it's always fascinating to watch debates over what could be major departures in future social norms -- like the high-meat diet that currently seems so normal, and the low-meat or veggie alternative that still seems rather eccentric or "preachy" to most.

The difference between theory and practise in practise ...