I can’t remember who said it (Simon Phipps?), but a while back this idea stuck with me.
If a company tries to open source a project, but gets nervous about it and tries to retain too much control, they can end up at a sort of open sourcing local minimum, where they are getting the disadvantages of open source with none of the advantages. In other words, they incur all the expense and hassle of setting up an open source project, without getting the increased community involvement and eyeballs which are the reward, because potential contributors can see that it’s not a project they can have a real ownership stake in.
Sometimes, half-done can be worse than not done at all.
I can think of a couple cases where this has happened. Biggest that comes to mind is what Sun/Oracle did with OpenSolaris and Java…
I think that still sometimes it’s purely deliberate, when they want to claim themselves as open source, but consider external involvement as a PITA.
Even for the good students of open source, patch that come from “external” sources usually have a much harder time than the one contributed “internally”.