Yeah because everyone who has a user experience feedback about a piece of software is magically a skilled programmer? The smug "PRs accepted" doesn't help anyone. Expressing hope for a feature at least shows potential implementers that the feature is wanted.
I felt I was replying to rudeness with rudeness of a similar tone. GP called an open source project "sucky" for not having a feature they wanted. Calling that "expressing hope" feels a stretch to me.
There's a certain rudeness to imposing your own ideas, but that does not apply here. It's not their idea. It's a standard feature of video apps that's missing.