JosephBlowski, I agree that the auto turret spamming in XPM is lame, but you exaggerate if you say anytime someone lays a turret to protect themselves means they're a noob. Maybe they have 2 health, and need a little help. Maybe it's not his skillz he's worried about, but the fact that he's about dead, and needs anything he can get to stay alive against your full health and shields.
Same with the guns on the vehicles. Why isn't it legitimate to hop into a vehicle and use its weapons when you know you're out-matched, or low on health, or whatever? They're in the game for a reason--to be used. Now, walking 100 yards with your back turned is stupid, as you say, but even when someone hops into a veicled, you can take it out easily enough. Dogde, jump, jet pack. You can get away and take them out in XMP. Nothing boosts your score like electrocuting a jugg with a person or two in it.
Oh, and nothing is as satisfying as a gut blow, so that may be why people drive all over the place.