Because realism has its ups and its downs. On one hand, it's tough and the teamwork is far better than any other style of game. On the other, if you just wanna run around like a nut and let off some steam, RO's the last game you wanna play (if you're a hothead like me, anyhow).
I find it tough to answer a question about what's next, tho, when we just started playing RO. With more maps and soon the tools to make our own (which means tons of new maps from the community) RO's not about to get stale just yet.