Because I suppose it's good for a laugh, though it's 100% piffle.

I don't know if I'm misreading how you meant this, but from the way that's written, it looks like you joined in to ridicule it.

Look, afew, I will never, ever tell you to believe in astrology, nor will I tell you to stop personally thinking of it as piffle. But the open threads, and even some diaries, have extolled the virtues of such topics as alcohol, drugs, ayurveda, kittens, road trips, Leicester, cars, gardens, and Harry Potter, and I can guarantee you that anyone reading that sentence recoiled internally and thought, "But there's nothing wrong with that topic!"

That's my point; as annoying as astrology is to you, it's not annoying to others, and a topic that you like to discuss might annoy others (I rejoice in kittens, but there's probably at least one ETer who can't stand the sight of them). So please realize that it's somewhat unrealistic to try to prevent most topics from being discussed, especially by deciding if they fall in the realm of science. I'm trying to be careful how I phrase that because I know you're pretty much just expressing an opinion, but others are going to have their opinions too.

I don't know if I'm being clear or just confusing the situation more, but mmmm has a good point with the drug diaries and threads. Not everyone here is thrilled with those, I'm certainly not. But I've stayed out of them for the most part (I had like one or two posts regarding lung problems) because I know if I tried to stop them there'd be hell to pay. No one would stand for my ridiculing drug use or telling people to stop talking about it. So I'm amazed that astrology elicits the response it does (you've been relatively calm, but I've gotten a couple of rather nasty replies in earlier diaries).