Sensible precaution -
It costs so little, and it can mean so much. You are far more likely to have a heavy landing than a mid-air. And an impact cushion will save more than your butt; it could keep you from spending the rest of your career in a wheelchair.
I'm talking about that special impact foam as used in racing cars. It doesn't weigh a lot. If you own a plane, get one and a spare, if you rent, buy your own cushion and don't apologise for using it, from the start of your training and afterwards.
Crash protection is built into every car these days, not just racing cars. Most aircraft were designed long before this became the norm.