I guess they really don't like melee characters and/or don't really know how to give them interrests.
Melee can definitely be interresting without tons of features.
I don't think there is an easy fix. If we try to keep things more or less grounded, there is only that much you can do with a melee or ranged character. In a team based real-time game, I don't necessarly feel that's a problem - gaving more and less micro-intensive characters works well. DnD3 and pathfinder add bunch of modals and passive abilities to melee characters, but I was never a fan of it - I generally prefer active tactical abilities, then passive character builds. In the end, to me it feels the same as swinging with a genereric fighter in BG2, it's just too easy to create someone who can't do anything useful.
While, like OP mentioned, D:OS1&2 spread active between melee and spellcaster archetypes the downside it made every character feel more or less the same - not much distinction between magic and non-magic characters.
Rather then making everyone active, I would prefer if BG3 focused on synergy between classes - that's what I always thought DnD was about. buff/debuff with one, hit wth the other.