IANAL
but even I can understand the GPL. Even before I read the GPL FAQ.
I assumed that, as MS is a business company that deals with software (rather than the other way round) they'd understand it too. Time to change the law firm to a company that will advise you rather than tell you what you want to hear guys.
Even Skype, D-Link, Cisco, Supermicro, Verizon, Extreme Networks, Xterasys, Buffalo, Micronet, Aopen, Gigabyte, Asus, Securepoint, Edimax, TomTom etc. appear to understand it, although it took the courts to tell one or two to understand it. Strangely many seemed to have thought that the lawyers letters would stop if they ignored them.
If you write code, license it how you want. Nobody has the right to criticise you. If someone wants to use they play by your rules.