I think now is different. I think crowd-funding has changed the economics of such projects from a few passionate hackers working in their spare time to now being able to fund people working on such a project full-time.
There's probably tens of thousands of users willing to pledge $100 into escrow on a Kickstarter-like service, paying out when somebody to creates an open Oculus Quest firmware capable of 6 degrees of freedom using inside-out tracking.
This funding model and skillsets are suprisingly close to what's required to provide Android security updates to older phones and tablets, so there's a broader business to be built.
Many of those users are probably willing to pay a few dollars a month so such software gets continued to be developed.