I thought it was because a multi-billion dollar firm pushed onto other multi-billion dollar firms with long-term expectations of them making billions more if they made targets of market share. And this occurred for both sides.

Average VC startup isn't going to be a Linux or Android as one is an outlier (like Red Hat) and other happened due to investment by corporate behemoth that was pro-OSS. Probably also an outlier given most aren't pro-OSS.