While "writing UA" about a bad FA may make you feel better (and actually go in the FAs record), has anyone just said to the captain/FA when deplaning "Just so you know, FA -name here- is rude and unprofessional. I don't fly UA to be treated this way"? If nothing else, it might entice the captain/head FA, etc. to say something to the offending FA (assuming youo havent already called the lead FA inflight to complain).