If your goal is to advance discussion in a meaningful way and the short version fails at that while the long version is too long, the same reasoning applies.

And what if the short version only fails when the person you're interacting with is more interested in point-scoring than engaging with your actual meaning? So that, e.g., if you say "some people will do X" they'll derail the discussion into a side-argument about how "some" could mean "only one person ever" even though even the most halfhearted application of the principle of charity would make it clear that if you meant "only one person ever" you would have used different words?

I can easily produce polite, bland, dry, and technically correct writing, but there is not much fun in that

But no one here is suggesting that you (or anyone else who doesn't want to) should be doing that.

There are plenty of LW participants whose writing is immediately recognizable as theirs, and not bland and boring and beige. Only two are immediately recognizable on account of their dismissiveness and rudeness to others. You are one; the other ... well, let's just say that he goes by many names.

The point here is not that you are "too weird". Weird is fine. The point is that it is possible to be weird without being obnoxious.

The above is harsher than I'd like to be. I consider your contributions overall a clear net benefit to LW, and your karma strongly suggests that others do too (unless of course LW is stuffed with your sockpuppets, but I'm guessing not). But they would be a bigger and clearer net benefit if you were to turn the dismissive sniping down one notch; and no, doing so would not make LW a monoculture. But it might be marginally less fun for you, and if that's all you care about then there's not much anyone else can do about it.

a single standard of expected behaviour

That's importantly ambiguous. Interpretation one: "we shouldn't expect everyone here to behave exactly the same way". Perfectly true and perfectly irrelevant; no one is expecting that. Interpretation two: "there's no norm we should expect of everyone here". Perfectly ridiculous; there are plenty of expectations applied to everyone, on LW and everywhere else.

We expect people not to reply with total non sequiturs (unless doing so in some particular case is hilarious or something). We expect people not to issue death threats. We expect people not to use LW to spam advertisements for their penis enlargement pills. We expect people to post in English unless there is a special reason not to. All these, and plenty more that I'm sure you can come up with yourself, are part of a "single standard of expected behaviour", which is not at all the same thing as a monoculture; and there's nothing wrong with that.