I like the definition of legacy code as untested code, since it means your fresh pile of untested crap is immediately legacy code someone will have to deal with

I like the definition of legacy code as untested code, since it means your fresh pile of untested crap is immediately legacy code someone will have to deal with later -- often yourself. Refactoring (for testing or not) is something you can do without the company 'allowing' it or adding 'dedicated trust work time' to the schedule. Sure, it does need buy-in from whoever reviews/signs off your commits if they bother to ask why you did that thing, and in pathological cases you'll have to keep a test suite to yourself / a local environment, but the social issues seem less of a barrier than people just throwing their hands up at perceived technical issues. I like recommending Feathers' Working Effectively With Legacy Code since it serves as a technical reference of solutions to the usual technical challenges/complaints that hang people up.