I think we're in agreement that Linux is in a better state than the browser. To nit-pick at your argument, Linux development is driven by people who are interested in working on it; many of those are lucky enough to have employers who encourage them to use a company email address to submit changes, and part of their working hours. Nothing indicates they wouldn't still be contributing without the @intel.com attached to their name.
Furthermore in the study you are referencing, the "8% volunteers" is larger than any company's contribution besides Intel and RedHat - even more if you add in the individual "consultants".
https://www.linuxfoundation.org/blog/the-top-10-developers-a...