Read some of the guides that have been posted in older LI threads. Some are very detailed and provide viable strats for melee heavy groups. Contrary to all the BSing and QQing ranged DPS is not required if your group is halfway decent with a solid strat.
What kills it for me is when you get a random group. The standard ranged strat is much easier for random people to grasp than the more complicated melee strats. I still do LI with melee, I just put together pre-mades for it.