The weapons placement in most of the maps are a bit of a problem. In many maps, blue team spawns with an advantage because they are closer to power weapons. In some maps, red team has the advantage because of the same reason. Reflection, Sword Base, Pinnacle, and a few others spawn teams ridiculously close to power weapons. In Reflection, the blue team can get the sniper and the sword first, and have a competitive shot at the shotgun and rockets. The red team has to haul it to shotgun and rockets to be able to nab them. If someone with any skill and a jetpack grabs the sniper, they can usually pick of the red guys going for the rockets. And the guy who grabs the sword can go up top and cover the sniper. With Sword Base, Blue Team spawns ridiculously close to the sword, and can easily get to the sniper or shotgun with a jetpack. See a pattern here? In both cases, Red Team has to grenade spam or get very lucky to get any power weapons. In Pinnacle, the blue team can jump down right after the spawn and go through the teleporter and grab the shotgun or sniper. There are only three power weapons ON Pinnacle, and blue team has immediate access to two of them right off the bat. The only centered power weapon on that map is the Rockets.
As far as the symmetry argument I saw earlier, Powerhouse is an asymmetrical map that doesn't give any power weapon advantages away during initial spawn. Both teams have equal runs to the main power weapons (Rockets and Gravhammer). It's not THAT hard to be able to place power weapons evenly on an asymmetrical map. Even a newb like me can do it pretty easily, and the guys who made those maps are supposed to be professionals.
And the last point, risk. For many of the maps it's easy to be able to grab power weapons, and there isn't much risk involved. When I used to play as a team in Halo 3, I used to hear "Someone's going for the (insert power weapon here)!" and we would all coordinate our fire on that area. Now half the time you can't even SEE when someone is going for a power weapon. The other half of the time players can literally use the power weapon they just picked up to great effect.
This is the main reason I play SWAT and Snipers. Not because I get owned all the time by unfair power weapon placement, but because I don't like getting cheap kills.
I have to whole-heartedly agree with the OP on this one.