You can switch between the two with a little effort. If I were human/sage I'd rather jack up my gains science on top of the usual economic sciences - Crime is situational, but Gains is always good in war. You can still get better Crime science than anyone who isn't human or sage, or at least equal.
A large factor in making a/t suck now is the lack of good gc targets due to the number of players leaving, and the new intel system draining stealth. Money theft was one of the ways a/t make their economy work out of war, and now it's significantly harder.