Re: how is google more stable?
Public cloud providers are not unstable, unless you try to use it as a normal hosting facility, but then you are doing it wrong (and wasting money, at least price/performance-wise). While any computing instance could die at any time (without warning), if you use it correctly, it is much more stable than normal hosting:
The idea is that you have small instances with a load balancer in front. If any of them die, it's no problem, besides a few customers losing a single request, and their next request will probably go through fine.
If you suddenly have a million requests from Slashdot, an auto scaler can start extra instances for you.
Amazon has had two major outages in the last few years, and both were limited to a single facility.