From my experience in 15 years of mobile development - there are developers out there who are more interested in building great software rather than building great products. The framework that they work in is the highest order of priority, and everything else is secondary to that.

If a new requirement comes in, they will pass it off as "impossible" or give it an incredibly high estimate, when in reality, it just needs a little creativity and doesn't work in their self-imposed limitations of the application.

Not to say these developers aren't useful - they are great at cleaning up and organizing messy codebases, but it can easily be taken to an extreme, at the detriment of the actual goal of the project.

But again - I don't think this even applies only to developers - it is all industries. There are people who optimize things for a better end-user experience, and people who optimize things for their own personal/team work experience. Ultimately you want both once your team grows beyond a handful of people.