Plus. I think that there is a bit of developer-psychology-101 here.
Most developers would rather go: This project sucks. This shitty language has not got a proper type system. Let's build a compiler/type-checker/use-this-cool-alpha-from-bingo-banana-I-found-last-night.
Rather than: This project sucks. I cannot believe how much bad, disorganised code we have written. Let's sit down and look at our mess to see if we can improve the way we write code, work together and in general develop way we make software.
I don't see these as mutually exclusive. Introducing a compiler/type-checker can be (depending on your situation) a very concrete way of improving the way code is written.
Most developers would rather go: This project sucks. This shitty language has not got a proper type system. Let's build a compiler/type-checker/use-this-cool-alpha-from-bingo-banana-I-found-last-night.
Rather than: This project sucks. I cannot believe how much bad, disorganised code we have written. Let's sit down and look at our mess to see if we can improve the way we write code, work together and in general develop way we make software.