DRG here, the problem comes down to a simple equation of risk vs. reward. Melee DPS are have higher risk in combat, and thus, should have higher reward. I see two possible solutions to this issue:
1. Greatly increase melee damage output (currently I can spam skills till the cows come home and never steal hate).
2. Greatly decrease ranged damage output (currently they have little risk with equal reward to melee).

The problem is not with positioning, it is not with support abilities, it is simply DPS. Why bring a risky DPS vs a safe DPS if they both do the same damage (and the less risky DPS has support abilities as well)?

Additionally, melee LB are not required for most fights. Contrarily, support / healer LBs are preferred in most end-game fights.