It's just how his voice sounds to me, I can't help it. I tried playing as maleshep in both ME1 and ME2 and in each case I never made it past the opening section of the game. I haven't even bothered to try in ME3, because I know I would never make it past Mars rofl.
There's so many voice actors I would've preferred. The guy who does John 117 in Halo. The guy who does Nomad in Crysis. Hell, I'm sure John DiMaggio could've cooked up another voice, that guy is crazy talented. Fred Tatasciore would've been a good pick if he hadn't already done Saren. Anyone, really. Just not Mark Meer. It's nothing to do with the quality of his acting, and everything with the fact that I just really do not like how his voice sounds.