We use the full Stack just like alot of the firms around us, i have a feeling the foss Linux crowd is trying to say otherwise its not popular blabla fact is alot of Dev happens there its not a deadend..
I think the ratio of open-source contributing company ia going to be much lower around the MSFT ecosystem than on others. This does not mean less work or less skills are around, they are just less visible. Case in point: node and the whole JavaScript ecosystem seems to have a bad case of the look-at-me's...