People do seem to have trouble performing a convincing rush in gpp, whether this is due to a lack of teamwork, players getting overly precious about their tremstats and being too scared to suicide rush or something else, i'm not sure. On a couple of occasions i've been on a human team camping astonishingly successfully to defend a very poor base at SD, a quick teamswitch, evolve to adv. mara, zappy zappy, suicide and repeat, and soon enough said base is no more.
I only play for fun, and camping to preserve one's stats is anything but.