As far as I can tell, the reason for the lack of companies is that they've made it impossible to monetize "software for other people" and apparently vast swathes of what used to need management are now "I can just build the parts of that I care about, it doesn't have to be good enough to ship to anyone else." (This horrifies me, though there is a silver lining: the value of the "idea guys" has also gone to zero :-)