Trust me, there are arrogant developers out there and they suck to work with. They treat code and design reviews as chest beating exercises. They refuse to work on anything remotely legacy. If their idea or design gets questioned in any way they get loud and obnoxious. You can't mentor these devs at all.
You have to be careful what you're good at. If senior devs/management sees you're good at legacy, they might task you with that as a majority of your time. Then your career plans get sidetracked because you won't have as much time working on the stuff that you want to work on.
Some developers are okay with legacy, but if they aren't, it's not surprising. Some legacy stuff is absolutely horrible to work with - it devolves into "get-in-get-out" fix mentality (and security issues usually get swept under the rug). Some legacy products are good though and require minimal tribal knowledge to actually work on.
This has happened to me twice at two separate positions: bait-and-switches about what I'll be working on because more senior members wanted to offload the legacy work themselves.
The general arrogance is really a separate trait from willingness to work on legacy IMHO and I agree on those points.
I agree with all but the last sentence. Every dev has a different background. Every dev needs to adjust to a different style of work wherever they go. Some will figure it out on their own. For the rest, I find it hard to believe that adding a mentor into the picture doesn’t improve the odds.