This user is just the latest in a series of spammers since Lemmy has grown in popularity. It’s hard to tell if they have some vendetta against the platform or are just maladjusted and want to annoy people having a good time.
As someone who posts across Lemmy a lot, I am usually made aware of the spammers almost immediately, because my inbox will be full of the same spam comment replies all at once. I just report them up to the various instances when I see it.