Has anyone ever considered that Maybe Tommy wasn't very upbeat at the ceremony because his homophobic former captain was there and ruined his whole day and likely made him uneasy?
And maybe Buck was being his silly goofy golden retriever self to try and keep Tommy in good spirits?
Which only worked for a short while because Gerrard approached him specifically to harass him and basically called him a fairy. He knew Tommy transferred from the 118. He was purposely setting him up to be homophobic to him. He only approached Tommy to bully him.
So then, protective Buck had to come out and give him a nasty glare while Chimney stepped in front of them and put Gerrard in his place one good time.
Well ofc nobody's thinking about any of this because they don't like Tommy so they don't care about his feelings.
Tommy has consistently come through for the 118, Buck especially, and the one time he needs cheering up and support, people see him as miserable and "bringing Buck down" and they enjoy a moment where he gets hurt.
We have seen Tommy happier, laughing/smiling more and way more upbeat in other episodes.
How much fun did you expect that man to have when a homophobic demon that he wanted to be away from, is 10 feet away from him (and will soon approach him) on what's supposed to be as special for him as it was for everyone else.
Whether people like it or not, and whether people want to humanize his character or not, doesn't change the fact that the decision for him to have a hurtful moment was intentional to give him a piece of the "ghosts from your past" storyline that everyone else is impacted by, to emphasize that Tommy is part of the current story and his character matters too.