Most people want to be sincerely praised. Someone who reads this post and applies it poorly is going to be saying praise while their body language says something else entirely. Or acting out of character for themselves, leading the reinforcee to suspect that the praise is insincere. Or they may go around praising seemingly everything, causing the reinforcee to interpret the praise as meaningless noise.

There are lots of ways for using praise as reinforcement to go wrong, and if someone is in one of those environments for long enough they will end up being conditioned to interpret praise as neutral or negative.