Hi!
I will assume good faith for the WMF. I was just making a quick jab; I know the WMF is not going to make MediaWiki proprietary.
However, I will not assume good faith for every other software company out there that may take MediaWiki, modify it or improve it in some way, and then begin selling it as proprietary software. It's nice to think the world
I'm in the free software world for more than two decades now, and I still fail to understand why this scenario bothers people so much. There are a number of projects that do exactly that, on top of various free software projects (both non-GPL and GPL), and so far I've not seen much problem coming out of it. Let's assume for a minute that we live in a nightmare world where there is a company, say EvilWiki Corp., which improves mediawiki somehow and sells the result. How exactly life in that world substantially worse for us than in ours where EvilWiki Corp. does not exist?
is an ideal place where everybody shares their source code, but unfortunately we are not living in the ideal, and in fact that is the entire reason the GPL was written in the first place: in response to companies acting in bad faith.
It is true that GPL is a response for that. What I am less sure about is that it is the *right* response. There are dozens major successful open source projects that have permissive licenses, or hundreds if you relax the criteria of "major" somewhat. I have hard time remembering one of them that seriously suffered from the nightmare scenario as you describe - maybe there are, but if there would be many, I'd probably hear about them, so I assume such cases, if existing, must be rare (or I am exceptionally ignorant). Some time ago, open source was a weird phenomenon with a shade of crazy - what do you mean give your code to everybody for free? Isn't that some Communist plot? I assume in these times adding some legal power to the movement was a very enticing prospect. Now, open source is a proven thing, everybody does it - Apple does it, Microsoft does it, IBM does it, Google does it, everybody who's anybody does it. It's in fashion. You don't have to force people to follow the fashion. So I wonder if spending time worrying about if the license is strong enough and defensive enough is something worth doing now.