Yeah, I never go through intentionally adding extra IDs in order to protect against something which might or might not ever happen. That would indeed not be a good use of my time.
However, sometimes I’m looking at observations for research, or out of curiosity, or just to look at pretty photos. And since I am already looking at it, adding an extra confirming ID is probably at least a tiny bit helpful, so long as the effort involved is negligible. (If I have to get out six different books, then no, I’m not identifying that. But if it’s a Yellow-headed Blackbird, I’m going to identify it.)
To be clear, I meant that it is fun to identify things that you are able to identify. I enjoy identifying Yellow-headed Blackbirds, so if I see one, I will identify it. There doesn’t have to be any more reason than that (for adding good-faith identifications).
Adding or agreeing with joke IDs because you think it’s fun is acting in bad faith. Adding careless identifications because you think it’s fun is just careless. But it’s the being careless and the acting in bad faith that are the problems in those cases, not the having fun.