there is no right or wrong answer to this question thus a waste to ask
its all preference
If you want the general feel on things, playing melee is usually much easier because you don't have to participate in mechanics and many outright don't even target melee (there are fights where the reverse is true, of course). However, simply because you're ignoring a mechanic doesn't mean that everyone else can too (you need at least X ranged out of melee range for melee not to be targeted), so its basically a shift of responsibility onto other players.
Of course, theres ultimately only a certain amount of players that actually need to be hitting adds or standing outside melee range, so its not like theres much benefit to a ranged loaded raid.
I honestly dont think i would have that issue playing my lock/mage/spriest.
I dont fully agree, they shouldnt position themselves behind you, but as melee you cant be static (pools) still gotta be in melee range and have far less area overall to stand in, specially towards the end.