Have you tried adding an article recently? I haven't had any trouble with my additions in a while. Some years ago there was a lot of deletionism, since there were still people like Larry Sanger around who thought Wikipedia should be a smaller, more traditional encyclopedia. In the past few years I've been occasionally writing articles on a variety of things, and nobody's complained, as long as they're well-referenced. I wouldn't say I'm a very active editor, either; probably 2-3 articles a year, so it doesn't require doing it constantly. I pick a topic (most recently, a Greek archaeological site), find 3-4 good references in, in this case, archaeological journals or monographs, write an article, submit it, and that's that. I haven't found a need to get approval from an Archaeology Cabal or anything. People sometimes come by and fiddle with the article's formatting to make it fit some kind of standard (adding infoboxes, etc.), but I haven't had unfriendly reactions.

The articles do have to be well-referenced, of course, since an article that doesn't cite good sources isn't very reliable. It also helps to pick things where you don't have a conflict of interest. Many of my fellow academics who run into trouble did so when they tried to write an article about themselves, or their research group, or one of their own projects (or worse, some kind of holy war they're involved in).

I haven't. I gave up because the experience was too much of a pain.

And that's part of my point: first impressions are the ones that last.

Fair enough, but I while I think there are plenty of things that could be improved about Wikipedia, imo it's hard to improve much without accurately understanding how it works. In these kinds of discussions I find a lot of opinions based on third- or fourth-hand information people have heard somewhere about Wikipedia, which isn't the best basis from which to work.

Well certainly the position is going to attract a certain kind of person whose editorial interests are pretty much required to be at least to the level of a hobby. I suppose you could say that the absence of amateurs in these spaces is an inversion, but I don't think it's realistic to expect that that to be the rule on a site the size and scope of Wikipedia.

What's missing from the site that would make it open and inviting again?

I think that shooing away the deletionists would be a great start.

There's also an annoying culture of instant reversal for pretty much any change. The headline says: "improve me!". The small type says: "and some editor will undo it!"

AFAIR there are reversal bots, to prevent vandalism.

And that's a perfect example of what I mean.

The problem is that it is no longer enough to be a subject-matter expert in order to contribute to Wikipedia. You need also to be a Wikipedia expert so you can navigate the hidden layers of bureaucracy to get a change in.

Many actual experts notice a small mistake, correct it, then watch in amazement as their changes are reverted. Do they know why? No. Do they care why? They shouldn't have to. Most of them never come back, forever diminishing a) the pool of potential contributors and b) the potential total value of the knowledge in Wikipedia.

The entire point of a wiki is minimal drag and minimal upfront commitment. The interface still promises that, but everything that happens after an edit shows that it's just the facade that remains.

Perhaps Wikipedia should work like GitHub, pull requests?

Wikipedia plays such a role in today's information access, that leaving it to 'the people' is simply impossible. In the end, Wiki is a powerful media, it's impossible not to acknowledge the potential huge profits of propaganda and advertising. If something is worth having, then it's worth cheating for. Sticking 2 cents into one of the most powerful sources of information on the internet is definitely worth it.

Leaving it to "the people" is the entire point. The entire point.

The hidden layers of wheels within wheels ("Oh, I'm sorry, did you not know to go to /wiki/talk/kafka/machiavelli227-chat, which is nowhere linked to, in order to resolve your issue? Too bad, the matter is closed forever.") are not necessary. It's more about warts developed to deal with internal bunfights than actual problems from actual abusers (which are mostly dealt with sensibly).

> it is no longer enough to be a subject-matter expert in order to contribute to Wikipedia

It's neither sufficient nor necessary.