I don't think bringing in Intel as an example is fair nor correct.
Intel can ship their processors without specific Linux support if they want to and the Linux code is not inside the box they ship.
Doing feature development like Intel or IBM can afford has interesting dynamics. For starters: not much secrecy. Secondly, no time-to-market pressure. Thirdly, the freedom to pick versions and platforms you want.
In contrast, most embedded vendors (and for now, I'm putting Google in that box, too) ship a Linux inside their box, running on some platform the software guys didn't choose.
If they take the time to merge their code upstream, they cannot ship.
And yes, many companies have failed by spending too much time in the community. Just compare the amount of announcements on LinuxDevices.com with the amount of code merged and the amount of products shipped.
When doing embedded development, your boss will only allw you a small window in which you can merge stuff upstream and benefit from it at the same time:
* after the prototype starts working
* before the code freeze happens
That period - in most cases I've seen is only a month or so - will be quickly over if you get push-back.
And then the madness of everyday work (bug hunts, etc) will draw you back inside your company.