I thought Larian's whole approach was to allow players to play (and enjoy) the game however they want. I strongly favor melee combat over everything else including especially spellcasting. Why is that "playing badly"?
Larian does like that approach, which is why they tend to design their custom game systems as classless. BG3 is using the class-based, rule heavy D&D 5e system, which does not work the same way.
BG3 is likely going to have encounters which are composed of various enemies who have different strengths and weaknesses, instead of all sharing the same strengths and weaknesses. Thus, a team which is entirely composed of the same playstyle may have problems when some parts of the encounter are strong versus that playstyle. For instance, a couple flying enemies which can attack from range might give your all-melee team a problem. Or maybe your warriors will all fail your Wisdom saves.
Why does everyone always want to interpret everything in an extreme way? I never said a totally melee party. I said I *favor* melee over all else.