Yeah, I've worked with the leave it alone types. What do you get in return? Components of your system which haven't been updated in the last 20 years and still run .NET 3.5. They obviously never stopped working, but you have security concerns, worse performance (didn't matter much in that case) and when you actually need to touch them you're fucked.

Why? Because updating takes a lot of time (as things break with every major revision) and on top of that if you then decide not to update (yeah, same coworker..) then you have to code around age old standards and run into bugs that you can't even find on Stack Overflow, because people didn't have to solve those in the last 20 years.