Emphasis mine.Honestly for players concentration break on damage is a unfun mechanic.
I wonder why we don’t seen more class feature, or feat, or items, or spells that would allow to maintain concentration despite damage.
It seems to me that usually when this word comes up, what it really means is that there are consequences for PCs that players don't like. Concentration is a mechanic that helps balance out the power and versatility of casters, and eliminating it just makes casters even more better. If losing a spell from taking damage is a problem, perhaps have the martials (the ones likely benefiting from whatever the spell is) protect the caster.
Consequences make the game interesting by forcing players to consider them when making decisions, thereby making decisions meaningful. Meaningless decisions are what is unfun, IMO.