Just because it's suitable for one game to use it, it doesn't mean it's suitable for any game to use it. In the case of BlitzMax you'll need to create a wrapper of some sort to use the library and there are associated licencing issues with that.
I don't see why. There are wrapper-mods for commercial libraries, and they manage to avoid contravening any licenses.
I've just downloaded the demo for Breakquest and after a cursory glance it looks like it's in breach of the LGPL - no copy of the LGPL licence, no source code or linkable object library in the distribution?
Perhaps that indicates that the author(s) of Dynamo are even more flexible than it first appears. Perhaps they're prepared to negotiate licenses with different terms, or even give them away, if they get a free plug or whatever. It had a copy of the LGLP license when I downloaded it a few months ago though.