I just wrapped up a campaign with a paladin in it. I honestly felt like the character's presence (mechanically) made the whole thing worse. The auras and generally high AC made the character and party quite strong, defensively. It wasn't just the paladin, but his was the character most responsible for the headache. I lost count of how many times combat basically devolved into him using the dodge action over and over while the other characters sniped from afar. Or he'd slug away during a boss fight never smiting, because he was fishing for crits. A 4 round fight would turn into an 8 round slogfest where the players never really had a realistic chance to die or anything.
And although the paladin was sort of the poster boy of that crap, most classes had access to some really stupid cheese that would trivialize fights left and right. The druid summoning 8 elk and doing 3d6+3 damage PER ELK in a turn by level 5. Or the halfling who took the luck feat and basically never failed anything meaningful over the course of 18 levels. Or the grappling crap where once the grappled target is shoved prone, the have no recourse (which is made worse by the fact that grappling is largely an uncontested combat action since so few monsters or NPC's have a proper athletics or acrobatics score, not to mention the grappling DC's for monsters that have it built into an attack are laughably too low to pose much risk).
All in all, I was really excited about 5e and loved it for the first few months. Everything is really kind of fun up until about level 5 or 6, at which point it just seems like the entire game is one big power trip. I can totally understand a GM saying no paladins for that reason, even if it wouldn't begin to address the real problems with the game (which have nothing to do with paladins specifically).
And although the paladin was sort of the poster boy of that crap, most classes had access to some really stupid cheese that would trivialize fights left and right. The druid summoning 8 elk and doing 3d6+3 damage PER ELK in a turn by level 5. Or the halfling who took the luck feat and basically never failed anything meaningful over the course of 18 levels. Or the grappling crap where once the grappled target is shoved prone, the have no recourse (which is made worse by the fact that grappling is largely an uncontested combat action since so few monsters or NPC's have a proper athletics or acrobatics score, not to mention the grappling DC's for monsters that have it built into an attack are laughably too low to pose much risk).
All in all, I was really excited about 5e and loved it for the first few months. Everything is really kind of fun up until about level 5 or 6, at which point it just seems like the entire game is one big power trip. I can totally understand a GM saying no paladins for that reason, even if it wouldn't begin to address the real problems with the game (which have nothing to do with paladins specifically).