I heard that the low PE of a company is with a reason:

a bad comapny without much growth.

I think the low PE of a market is with a reason, too: a bad economy without much growth. Fed HAVE TO do big QEs shows this economy is bad. Just like a person is taking drug shows that the person is sick.

But somebody would say this person has drug to take shows he is strong, would value he more than when he was not taking drugs.