Marauders are an issue yes, also LoS is a part of the game so it has every right to be used as a condition. As far as face tanking snipers, if we did rule out LoS then that means you're face tanking them.
Logic fail there.
LoS is a part of the game, granted.
You cannot be LoSing a sniper 100% of the time.
And lack of LoS is not equal to facetanking.