Im sure once you get past AA and KK EV is more a function of how well you play the hands in a No Limit game. Im sure JJ has a negative expectation for a bad enough player. This could certainly be a measure of potential EV though.

Playability (the ease with which you can figure out the best decision postflop) is a huge factor in NL. Thats partly why JJ can be -EV for a terrible player but its also why a hand like 22 is so much better than A9o. Its just so much easier to play 22 correctly in a reasonably soft game. Make sets + get paid.