Microsoft sells their software. We don't. You cant expect a commercial entity (which ya know, Ultimaker is) to invest in the products of the competitors. IMHO we're being kind enough as it is to even let others use the software. It's fair to draw the line at investing even more resources. Besides; the software windows sells is more valuable when more stuff works on it. They are making more money when they do this. We dont. Actually, we'd even make less as there would be less competitive advantage.
You're free to think of it what you will, but if you want the support i'm going to have to fall back to the old open source saying; "Patches welcome!"