Depends how hard your planting is
What Vila wrote concerning the feel of the elevator is quite important hence the need to avoid entering the flare with a thrust higher than necessary..too often seen as a technique to achieve a smooth landing...all it will achieve when the day comes is a large bounce.
Yes landing softly is in the passenger view important as it is a way if not only the only way to judge the skills of the pilot in front.
However i never intervene if my colleague is seen to come in harder than usual (as long as all is in limits) as experience of mistakes is a key learning fact...and i wont let a passenger feel go before that.
First officer is the time and place to learn by mistake.
So let them learn and when the day they get on the left,hopefully they will do the same.