During ZIRP-boom-times, having a successful popular open source project could be a ticket to kudos and a high paying job and a certain level of responsibility and satisfaction. BigCos spread the money around, and your job as a SWE ended up being gluing together a bunch of these open source pieces to solve corporate problems. And on the whole people felt like their corporate jobs were giving a fair deal, and a decent dividend for the open source work they were doing.
In that context why would you pick a license that your generous employer couldn't use?
The GPL and the free software movement is borne out of an earlier era, GenX and younger boomers who lived through seeing their hard work exploited and stolen from them. Or corporate entities that cut budgets, laid people off en masse, exploded in stock market crisis, etc and suddenly the good will was lost.
I think we'll see a bit of a resurgence in the GPL, as some people try to protect the work they've done.
(I do thnk the personality of Stallman himself has become a bit of a problem to be associated with)
