The biggest issue is that aim provides no bonus to our tech attacks. As a sharpshooter, this only applies to Sabotage Charge, XS Frieghter Flyby, Vital Shot, and Thermal Grenade. Ok, not the biggest deal there, one useful single target move, one move for when you're moving, and two AoEs.
With 972 cunning, I get 194.5 ranged/tech damage, 7.21% ranged/tech crit. This works out to slightly more than .2001 damage and .0074% crit per point.
By contrast, 98 aim gives me 19.6 ranged damage and .82% ranged crit. Or .2 damage and .0083% crit. You get a little bit more bang out of the crit on it (enough to make the miniscule extra damage on cunning worth the hit), but losing out on it on the aforementioned tech attacks really hurts aim's usefulness, especially in AoE situations.
Throw in the extra 9% cunning once you get into the saboteur tree (making each point worth .2182 damage and .0081% crit, and it's for both ranged and tech) and it becomes an easy winner.
Disclaimer: It's very late for me and I've got a bad headache, so some of my math may be off a little, but it shouldn't be much. Also, technically, the 3% extra cunning wouldn't increase a single point to those values, you'd need about 33 to get a full extra cunning point, I just figured I should keep working with the same values. A better way to say it would be that 100 cunning / aim would be worth 100x the values I listed.