Nobody has yet made a post here, so I question whether it is needed. As a sub-sub forum it isn't doing anyone any harm, but I think we should really try to make use of it. Article Evaluation, on the other hand, is a major sub forum, and should be made in to a forum all of its own, of equal weight to Wikipedia Editors (and some would argue it is more legitimate criticism).
Anyway, here are some ideas for what is wrong with the Mediawiki software:
1) All revisions are retained. If you type something and then immediately realise it was totally wrong, its still in the history. Even if you edited it to something you meant to say just a few seconds later. Too bad tough luck, its there. And the "woops" edit stays and seems to be the "diff" that people like to use against you when its convenient for them.
2) There is no ignore option. You can't prohibit someone from talking to you on Article talk pages, but worse you can't prohibit them from talking to you on your talk pages. So if someone wants to harass you, then tough luck you have to put up with it. Wikipedia, through their software, encourages stalking. Of course, hypothetically, if its serious enough then they will ban them from the Wikipedia. But so far not a single person has ever been banned for wikistalking that was actually stalking anyone. And what is so hard with banning someone from your talk page? Wikipedia should have it, with no punishments associated, as a basic human right. They don't. Wikipedia thinks that stalking is good.
3) Wikipedia allows people to "watch" pages. Sure, they say it is designed to stop vandalism, but realistically it is a list of pages that you own. Pages that you control. Pages which you will revert if anyone dares to change it in a way that disagrees with your POV. Who is watching the pages isn't made public either. There is no way of knowing if someone is watching a page. Thus it becomes a secret cabal, helped by the software.
4) The "watched pages" can include user pages and even user talk pages. So if you want to stalk someone, its made easy. On top of that, you can click on "User Contributions" and follow them around to continue your harassment of them. And this from a place that doesn't even have a competent article on cyber stalking. And one which amusingly protests about Wikipedia Review complaining about an admin who might be stalking (Snowspinner) and then insists that by complaning, Wikipedia Review are stalkers! Sorry guys, but until you fix up this software, its a no no.
5) The whole anonymous editing problem. It sounds good, since your IP address appears, but often its the wrong IP, or a proxy or something, and it changes all the time. Why not just disable anonymous editing altogether? Why not require a valid non-web based e-mail to register? And then maintain a block list of invalid e-mail address providers? Not too hard to do. But Wikipedia just allows people to lie, and then they expect admins to be able to deal with it. Its an impossible task, made worse by the abuse of this.
6) CheckUser is a massive problem. Why is it that so few people have CheckUser? Why don't all admins have it, so that they don't get fooled, and so that there is some kind of consensus about it? Because CheckUser is so secretive, there are lots of lies told about it.
7) Time limit bans. How ridiculous is it that someone can be banned (sorry, blocked) for 24 hours? Its ridiculous. You're either banned or you're not banned. Sure, you can be unbanned, but why put a time limit on it? Its just asking for abuse.
8) Block logs. What the hell is the point of a block log? Its like a criminal record. "Oh, see they have been blocked before". But the block log doesn't say the unfairness of the block or what it was for. Many people have been banned because they were earlier blocked over 3RR violations or due to stupidity by admins, which were protested and proven illegitimate almost immediately. There should be no block logs.
The whole public discussion of bans is ridiculous. They act as smear campaigns. Request for Arbitration and lists of banned users are inappropriate. They encourage stalking.
Basically, most of the problems with the software is that it encourages stalking. Perhaps Wikipedia need to recognise that yes, stalking is a real problem, and yes, they are doing a lot to encourage it.