u/Jigglepirate

I've got a 9mm PCC with a red dot, and people reccommend sighting it in for 25yds, or 50yds.

Is there anything wrong with sighting it exactly flat? Like if my dot is positioned 2 inches above bore, can't i sight it in so that at 10 yds, the impact point is 2 inches below where I aim? Is there anything wrong with this other than shooting at long range?