I think it's a shame many new developers will never see a mainframe environment (I barely did)... There is a massive amount of things that are just "done right"

I think it's a shame many new developers will never see a mainframe environment (I barely did)... There is a massive amount of things that are just "done right" (and plenty wrong) that are great things to learn from. So even if the technology is "legacy" - there is a lot you can bring forward to almost any domain.