Actually that only applies when you have a +% main stat boost from the tree. Without that, Power comes out ahead on Bonus Damage but doesn't increase Crit at all. With a +9% main stat boost they are within a few points of Bonus Damage but the main stat gives crit as well. That said, this only applies to Sentinels and Shadows, everyone else has a bonus to main stat.
Actually, even for Sentinels Strength > Power.
You might be thinking I just proved you right (just by 0.06 damage), but don't forget this was based off a columi character who start off with lower stats ceiling from the offset, what about someone in optimized rakata and above who are most probably already stacking enough crit? Is the extra main stat then really worth the risk of diminishing returns where you'll be losing a lot more than a small number like 0.06?
A few points.
1. DR on mainstat is very flat. You don't lose a "lot more".
2. Your math is overly-simplified. I don't want to argue it since it's been beaten to death by now, but search through LagunaD's posts if you really want to dig into it.