Let me give you some anecdotal evidence of the contrary. Dell selling laptops with Ubuntu, the "Tier-1 hardware vendor selling Linux from 'well known distribution'" poster child.
The brightness keys on Dells have stopped working properly for a year already (https://bugs.launchpad.net/bugs/207473). That bug has a bunch of "invalid" duplicates, therefore the large number of annotated fixes.
At the end of the day, Dell laptops shipped with Ubuntu still don't have a fix for this year old regression.
Anecdotal for sure, but 'Dell with Ubuntu' is still their poster child success story.