Testing? You think the people with such horrible legacy code would pay me to write tests? I am happy if they don't want me to edit it directly on the live servers.
But yeah good point with the testing. I should have specified that I am talking about agency work, not actually caring about the software you keep alive.
I have found creating test seams in legacy OO code easier than starting from scratch with an untested 5000 line procedural file.
In that case, having some abstractions was better than having none.
But that's just my opinion.