Who's to say software won't turn out like oil/energy. Before tech companies took the mantle of "highest market cap", Exxon & friends ruled the roost. [Google, Apple, Microsoft] look a lot like Exxon today, with their biggest defensive moat being scale.

Upstarts prove a new market (Pebble, Roku, etc.) only to have entrenched players take over and dominate. Or, you have to relegate yourself to very small SMBs differentiating yourself with support-costs:revenue ratios that bigger players simply aren't interested in