I agree with you, but just how much can we advance with stuff like AI now a days?I don't understand why people put an equals sign between higher specs and graphics power. Wii and the DS prove that greatly lacking specs result in releasing games that look as if they just rolled out of a time machine and realized they're in the future, games with very limited AI and physics, not just graphics. I can say that you play your 3DS more than your Vita because the 3DS currently has more games since it was released earlier however this state of matters is subject to change in the nearby future. If specs weren't important at all, gaming would just stop evolving at the level of Atari's.
Look at PC VS consoles, how much different is AI when comparing the current platforms?
It's something that requires a lot of work which is entirely up to the developers, hardware isn't a hurdle anymore since there's so much untapped potential even on the 360.
Also enemy counts only makes a difference for a small and specific genre of games, like beat em ups and the like. Anything beyond that requires too much work and money to be considered by developers.