Are bugs on one device more serious than bugs on another?

Overheard (somewhere I'd expect people to know better):

"Bugs in mobile apps aren't as serious as bugs in desktop apps."

Really?
What are the implications of believing this?
What happens when this is the prevailing attitude in the developer culture? In a company or in a wider community? Especially when "building once to run everywhere"?


The background to the above quote was that they believed that lots of mobile apps are buggy but desktop apps are generally of a higher quality.

I think the opposite is true (at least of good apps). The connection to mobile devices and the competition between apps mean that bugs are more obvious and developers work harder to avoid and address bugs as part of a greater focus on UI & UX.
On the desktop there hasn't, traditionally, been a great focus on UI & UX and quality hasn't been as great as users are more tolerant of bugs and a substandard experience as their expectations are lower.

Of course, in a brave new world of universal apps that run on multiple devices a bug can easily exist on both mobile and desktop. The good news in such situations is that you can fix it in both locations at once. But sometimes that might not be the case and you could have a bug that only manifests on one platform. This means you have to test everywhere.