Talentless developers who fight and argue are the only real hazard in the world of programming.
Mature trends and languages have attracted decades of developers good and bad, and because they're widely used, they have the misfortune of also providing a home to the largest corpus of terrible code.
Mark my words: in a generation, functional programming will accumulate just as much garbage, inadequately programmed by just as many careless and/or passive-aggressive developers desperately clinging to their jobs throughout the next wave of whatever becomes the next Steve Ballmer stack ranking code review process.
It doesn't matter how many words or ideas you throw at this circumstance. Terrible developers will still manage to commit garbage.
Life finds a way.