You hit as many positionals as you are able, if you are unable to hit the rear/flank for any reason, you can use True North, that's what its for. If True North isn't up and you can't hit the rear/flank, that's cool, just try get it next time, missing a few positionals isn't the end of the world.

You are suggesting they remove an entire gameplay element because it's mildly inconvenient to you, but for me and a lot of players who actually enjoy melee, they are what really make the difference between a good player and a great player, I see plenty of melee ignore positionals as it is, the game would only stand to lose from their removal, they wouldn't add anything in its place, so it would just make the melee less engaging because now I can just stand there stringing my combo along without any thought whatsoever, having to reposition for my attacks adds depth to the role.

Also in big pulls, there are no positionals, you mostly just clump as many enemies together as you can so they can hit everything, melee can stand in AoE during big pulls and heal it off with bloodbath if necessary.