I don't mind a bit of multiclassing, to be honest, although I agree that splashing in 5 or 6 classes gets exhausting.

5e limits this to some extent by placing level up rewards deeper into the class:


ASI/Feat are awarded every four CLASS levels (not character levels).
Multi-attack requires 5 class levels (no BaB stacking for multiple attacks).
Higher level spells require you to stick with a class (although spell slots do not).

Pathfinder does this a little bit, but a lot more stuff is front loaded (1 level of monk gives wis/cha to AC + a free feat for the most egregious example).