I'm going to work at a pizza place and any time someone gets a pizza with pineapple I'm going to put less meat on the pizza than the recipe says to punish them
I hope you are joking, you can't treat customer like that.
I've been a pizza cook since I was a kid and pineapples on a pizza makes me so angry.
I agree that pineapples on pizza are pretty nasty.  However, it's your job to follow the rules and please the customer.  You need to do what your job requires you to or you may not have a job much longer.
It's not like my pay depends on it and I will make a big deal out of it.
You will loose your job, they will see a pattern and know you're doing it on purpose. if you don't want to make people what they order, than get a different job.