There's a lot of money selling dev tools, but not necessarily Microsoft levels of money. Also, Sun was actually a hardware company if you looked at where their revenue came from.

Cadence, Synopsys, MATLAB, Mathematica, JetBrains, Windriver, and many others make a ton of money selling specialized dev tools. The key in that market seems to be specialization, though, so most devs don't see their work.