Getting Shit Done trumps all things. The reality as well is that the majority of the .Net platform (with the exception of the Standard Libraries, I believe) are open ECMA Standards (See among others, #335).
The reality is that .NET is a very probable patent trap for the FOSS community and Microsoft is trying hard to make us dependent on it.
Unlike .NET, Java has a free implementation (OpenJDK) and any code derived from OpenJDK is granted Java patents. Apache is a different story as they are developing a Java implementation under permissive license, which means that Apache code could be used in non-free software (including .NET), that would make Java vulnerable to the "Embrace, Extend and Extinguish" strategy. That is what Apache is paid for by Microsoft.
So my point is that supporting .NET is bad for the ideals of the free software community, yet it is good for pragmatic reasons as it could bring more users. And I have a strong impression that today pragmatism is favored over principle by the community, the decline of copyleft is also a sign of that.
There are pretty strong guidelines with regards to patents for any technology you turn over to an ECMA standard which basically removes your ability to patent troll by legal license.
Who sets these principles? I ask because FSF has bashed Apple and MS at various points in time. If the FSF is writing the religious-book here, then you're not supposed to work with the cloud, you're not supposed to use to chromeOS notebooks and boy you should really go dump those smartphones since they're either proprietary or open-but-not-quite.
In that same vein, code inside a car's sensors isn't open sourced and Toyota had a rather messy couple of months because of it. So boycott cars too ? Build your own car ?
I really don't get the excuses people come up with to complain about people getting shit done. A "principles based" fight is being fought in politics all the time; fat load of good that's doing.
Being a part of the hacker culture means sharing the hacker ethics, including the principle of information-sharing, which is the base of the FSF philosophy. These principles are not set by someone, there are what is meant by the word "hacker". If you do not consider these principles to define what the hacker culture is, then we are talking about different "hacker cultures". I use the common programmer subculture meaning of "hacker":
http://en.wikipedia.org/wiki/Hacker_(programmer_subculture)
Sharing the same ethics means having similar views of good and evil. Seeing something as evil does not mean you must boycott it, yet it is logical though not always practically possible to avoid what you consider to be evil.
The hacker culture is all about doing what you can, and saying "screw you" to anyone who tries to tell us what is principled or not. If you want to talk principles go to church.