FAIR IS FAIR...OR IS IT?

This has been a fly in my rum for a while. Why is it that if  defensive player jumps into the neutral zone causing an offensive player to move before the snap, whether or not that was the intention, it's a penalty on the D. But if the QB uses a hard count with the sole intention of drawing the D offside, and is successful, it's still a penalty on the D? Does anyone else see the injustice here?