Why is it harder to push with FH?

I've been practicing pushing more aggressively with FH, but for some reason I just find that it is much harder to push with the FH than it is for BH.

With BH, I can push more consistently and more aggressively. It is easier to put heavy spin, it is easier keep the ball low, and it is easier to get better speed and length.

Is there a mechanical reason why it is harder on FH? Or is it just me?

Inversely, it is easier to push short drop shot with FH than BH.