Maybe it's because the guy is a relevant public figure, and if he were to say something along the lines of "the bastard deserved it" he'd face a ton of consequences for it? This is so much easier to do in an online space where you are anonymous, especially in an admittedly echochambery place like lemmy.
I do recall the Trump's first assassination attempt, and some celebrities (can't recall the names right now) did come out and say something along the lines of "shame the guy missed" which made the media start hounding and targeting them, with their colleagues being forced to disavow or kick them from their projects entirely.
It would be cool if Tim Walz or any influential figure went "rip bozo" regardless though