Here's one non-abstract idea that you can get for free, even though I might try myself as well:

Give Confluence a run for its money.

Confluence is so bloated that a clean install takes longer to start than it takes to boot my laptop and log in.

Plugin SDK documentation is a mess.

As far as I can see it only sells because of the brand and because of network effects.

If anyone could manage to create a real wiki (remember, it means quick!) and market it they might have a chance at some nice cash that would otherwise flow to a company that keeps wasting peoples time.

End of rant ;-)