I had the privilege of meeting this beautiful boy and I can assure you that he was in no way upset, in discomfort, stressed or miserable about it - he was a very happy boy for whom the nappy (which he didn't wear all the time - only when he was out exercising - meaning he could eat his caecals perfectly well as bunnies really only produce a batch of caecals once or twice a day) provided a way of allowing him to exercise in comfort and preventing him from covering himself in mess, preventing urine scald and the need for lots of bathing to clean him up again.
I wouldn't necessarily say it's right for every bun and shouldn't be seen as a lazy option, but in the right circumstances I have seen that it can be very beneficial