I just have a few questions/comments about the current library policy for unix'es.
There's no need to prevent library/header installation with cmake. After all the built libraries are static, and as so only meant for development. Applications using bullet that are distributed as binary packages should already have it linked in. On the other hand, source packages should compile as long as bullet is installed, and keep on working even if it is removed.
Also, shared libraries are good. You just need to keep a copy of the versions you need for a particular program (this is done automatically by the distro's package system) and it should work perfectly. I can't imagine the chaos it would be if every piece of software provided its own version of every library it used (hum, I suppose it would turn out like window$
oh sorry for the rant
Summing up, there's no point in forcing a specific use on the users. Versatility is the key here, I suppose..