Some of us have been writing C in Linux for ~12 years and decided enough is enough. C++ is not any better (in many ways worse), Python doesn't really scale and is not statically typed, and Java is in many ways inferior to C# (C# is basically Java-done-Right - altho it too has some problems, but largely it really is Java-done-Right imho).
So what other options do we have?
C#, imho, fits the bill nicely, so I worked on Mono and MonoDevelop because the better these tools are, the more productive I am (as well as many other devs) when I (we) write other free software.
If you don't like C#, fine, don't use it. Use Java or Python or whatever it is you prefer. I'm not going to badmouth your choices simply because I prefer some other language, and I expect the same in return.
We are also not "injecting patent bombs into FOSS". Microsoft has issued a legally binding statement saying they will not sue. While this promise is not perfect (ie. it won't cover partial implementations of ECMA 334 & 335), but it *does* cover Mono because Mono is a full implementation.
Besides, even if this were not the case - you've obviously chosen not to use any apps built on Mono, right? So what "patent bombs" related to Mono are you worried about?
As with all things on the Linux desktop, every app has a bajillion alternatives (some better than others). The worst thing that can happen is Microsoft attacks and everyone switches to one of the alternatives and instantly everything is resolved and Microsoft walks away with nothing (because everyone switches to something else). Woopty-doo.