What the hell is going on . . . .

You may be surprised to find that it's not actually so strange.
The thing the web cam style offers that other mediums don't is interaction with a certain amount of anonymity still in tact (as in 'safety') and a relatively short trip toward getting in touch with parties with similar interests.

I'm guessing: Hormone imbalance (which some people call mid-life.) In the old days (ancient times before broadband,) guys were less open with their sexuality and would just get a Harley and a hot cougar GF on the side...