Ah. You stress the hoping part
of it? (I mean there should be not problem in saying "Sorry, gays are not allowed to donate blood.") Where's the problem, except it being highly amoral
Imagine someone hopes to upset/scare/annoy someone else by saying something, but someone doesn't get upset/scared/annoyed, and that in return offends the offender, who will now punch the other for not getting all upset about it.