The main source of those problems is not mysterious. The loose collective running the site today, estimated to be 90 percent male, operates a crushing bureaucracy with an often abrasive atmosphere that deters newcomers who might increase participation in Wikipedia and broaden its coverage.
This will be the demise of any and every online community. If you are horrid cunts to those who try to join, you will die a slow, painful, miserable death - and you deserve to. The very few times I have tried to add anything to wikipedia, they have been quickly removed with a non-substantial reasons for removal. They mostly seem to be "you're noob - gtfo" more than "revise to make it more X or Y. Great job on Z."
I'm not sure how one would ever spearhead such a change since their longterm volunteers are elitist and annoyed and they can't pay them to be non-elistist or less annoyed. Further, they can't "hire" new non-elistists because there is nothing to offer them to make up for noob treatment.
I am all for communities having levels of entry and ways to keep newcomers from completely fucking up the balance. But there has to be a path to success for any noobs. Otherwise you will end up with fewer and fewer people and this ever-shrinking group will become more tightknit than ever and block out more and more noobs. This will cycle endlessly until there is nothing left.