ATinNM: The socio-political justifications were either not mentioned or used as reasons for not joining.

Oh hell no.  I didn't even bother considering the socio-political arguments.  These are corporations we are talking about here.

Truth unfolds in time through a communal process.

i only selected those points that seemed relevant to corporate interests.  others they list on that page (and they go into it elsewhere as well):

What if we Left the European Union? - BERR

1. basic Single Market freedoms such as the right to live, study and work in Europe might be jeopardised;

4. we would lose out on EU funding for research, which currently outweighs our contributions, and would   no  longer be able to influence the development of the Framework Programme. [this one is quasi corporate relevant as well, perhaps even more so than socio-political relevant]

5. guarantees of important protections for consumers could be lost;

6. workers' rights could be eroded, making it harder for employees to find a satisfactory work-life balance;

7. one of the strongest voices for reform in EU would be lost, with the result that new EU rules would be more likely to be damaging to British interests; [this one also somewhat corporate relevant]

Truth unfolds in time through a communal process.

The EU was originally the EEC, and was defined exclusively as a trade organisation. So the original referendum was sold on the basis of economic benefits - Jobs™, etc.

Since then there's been a drift towards closer cultural and political integration. I'd guess some of the old timers feel this was never part of the deal, which explains part of the push-back.

But as InWales said above, we have our own 'patriotic' wingers who are captivated by a Disneyfied semi-feudal British identity. Brussels threatens this identity and promises a tidal wave of something bad or other.

These wingers don't much like anyone who isn't British.

They'll tolerate some immigrants as long as they work hard for them (middle and upper class) and don't steal their jobs (lower middle and working class). But the idea of being flooded by foreigners - i.e. anyone who isn't English British - makes them break out in a cold sweat.

The core problem is that plastic faked-up identity, and the constant media portrayal of everything that happens in Brussels as a rather floppy and bureaucratic dagger pointed at the heart of it.

And the reason for that portrayal is partly a genuine sense of outrage, and partly the expediency of being able to use public Euroskepticism as a negotiating position.

I'd guess wingers in other countries have similar motivations.

It's reactionary in the widest sense - perhaps because the UK has never quite assimilated the cool rationality of European modernism. The culture moved straight from paternal imperial arrogance to feudal volkisch nostalgia, with a side order of neo-Victorian business brutalism.

There was that hippy thing in the sixties, but apart from that UK political culture has been reliably grim, adversarial, antiquated and desperate. The only vision is a nostalgic one. Looking forward in a positive way is something that seems to terrify people.