> these are real, well run companies with good fundamentals
I'm not disputing that. But even "real" companies don't warrant P/E multiples in the three-digit range, unless there's a very good reason to expect them to grow their profits by 10x or more in the foreseeable future – and that has to be the expected value of earnings growth (roughly, the average growth over all possible futures), discounted by the time value of the investment.
P/E multiples over 100 are practically never justifiable, except as "someone else will come along and pay even more" – i.e., the greater fool theory.
Do you have a better hypothesis that would explain the extreme valuations of those stocks?
> But to say that each one of these has a high P/E because every shareholder is a fool is very reductionary.
That's not what "greater fool theory" means.