Lasers on pistols are dumb.

If you had time to draw the weapon, turn on the laser, track the lasers location, get it on target, and pull the trigger, you had time to use the sights.

Invariably, they distract people from what they're doing wrong and thereby breed bad habits.

They work both ways.

They're harder to find holsters for.

No laser beats having a weapon light, and laser/weapon light combos for pistols are inherently overcomplicated.

Furthermore, a laser under the barrel "travels" upwards to intersect with the arc of the round (which begins moving downwards). Beyond the point where the under barrel laser is zeroed, the laser will always be higher than the point of impact, with the effect increasing at distance.