Because investors hope that companies like Amazon will get a global monopoly on an entire giant segment of the economy, probably an "economic moat" reinforced by bogus patents or copyright or trademark claims (like Oracle vs. Google).

Think how the advertising business was formerly divided in thousands of small actors in each country (publishers) and now it's dominated by a handful of global internet companies.

This is an excellent question that I’ve never seen addressed. Replying just to call attention to it in the hopes that someone knowledgeable HN’ers can answer. It seems like cloud would quickly become a commodity but I have no special insight.

Call the cloud managed data centers and you have your answer basically.