Comment by Sylos

The Mozilla Corporation is 100% owned by the non-profit Mozilla Foundation, so any earnings that the Corporation makes, they either have to reinvest, put it to the side to reinvest it later or pay it out to the Foundation, where it's again in non-profit hands (i.e. forced to invest into their specified mission).

The only way that the Corporation could do shenanigans, is by paying their employees higher wages than would be necessary to hold them or is considered reasonable for the job that they do.

It was set up, because there's limits to how much money a non-profit is allowed to put to the side, which would have limited Mozilla's strategic flexibility.