We all know it's the right thing to do. It's an unpopular role with little solo carry potential compared to other roles. Support mains are doing us all a huge favor, and I want to make a point out of honoring them every game, even if someone else was very helpful. Just do it. If lots of people in the community start doing it, then more people will want to play support, which means less chance of being autofilled into that role if you don't want to.
So go out there and honor your support every game. Every. Single. Game. They deserve it, and you know it.
(Of course, this doesn't apply if they're an obnoxious, toxic piece of Urgot excrement).