I think one perspective for companies looking to hire FTEs is that at some point, those "job hopper" advantages are best captured by hiring consultants and other non-full-time people for fixed term gigs. (It's another question to ask the job hopper, too, why don't they go into consulting or fixed contract work?) Sometimes that will involve them writing code, other times advising/overseeing/helping some internal team, but at some point they've done what was needed and it's see you later. Your actual full time employees though, you want them to stick around.
The last big company I worked at made it pretty easy to "team hop", which I'm sure cut attrition to the company overall by quite a bit. There was even a cool "sniper team" that would move around to assist different teams every few months. And of course there were the summer interns, most teams tried to make them net-positives and productive during their few months -- that is, even with some overhead of spinning up to the environment, having some team members mentoring them, and having to make sure their work is well understood enough by others to survive them taking off, you're still happier they were there than not. But IIRC no one was directly hired onto the sniper team, they were internal transfers. Maybe some were job hoppers in the past. But most teams interviewing new outside candidates for FT roles want the same sort of expected stability as everyone else, so of course too frequent job hopping isn't going to be seen positively.
I had a fun experience interviewing someone for a management role, he had previously left the company (after a year or so as a dev and about the same as a freshly transitioned manager) for another, but after maybe a year and a half or so at the other was thinking of coming back to the old one. I can't remember my phrasing but I basically asked him what sort of guarantees (I know I didn't use this word but it captures the desire) he could make that he wouldn't just leave again after a year or so, when this particular position really needed someone invested for at least 3 years. His answer was something like a pretty floaty "we never know what life will throw at us", which sure, there are no real guarantees here, but still, you could at least try and make me believe, like demonstrating a passion for the underlying product space or something, or heck even a simple mercenary view of trying to get a lot more RSUs that don't vest after that many years would be acceptable to me (if not others). Anyway, I recommended against him, for that and other reasons.