In my opinion the biggest problem is that most companies are doing development for projects. If a project develops something that is worthwhile to be published as open source the commitment for maintenance can only be given till the project is finished. After that no more resources are available for further developments, support of the community, bug fixes etc. This usually means a slow death for the open source "product".
Also, some companies are very eager to look at the PR for things they publish, and this usually means to go through all the processes for publications. This is something which in general overwhelms engineers and programmers.
