Compare these two ML 12 items:
+1 finesse dagger of puncturing
and a
+5 dagger of puncturing
Both are ML 12, but I question the relative value of the finesse enchantment.
Realistically the +2 dex is likely to be meaningless at level 12.
My drow sorcerer with a 14 STR and a 26 DEX would pick the finesse dagger because it would offer +2 to hit over the +5, but much of that value is based on the on crit effect.
Any move to weaken on crit effects should probably also feature a drastic reduction in the ML requirements for the finesse enhancement, otherwise there will be very, very few instances where it makes sense to use a finesse weapon.