This seems like much more of an opinionated lint-y thing than the other warnings we throw out. There are definite valid reasons for wanting to shadow names - for example, often I want to hide an old version of a value in scope, or if #3245 is rejected, it enables an alternate workaround for nested do with differing bind.

It's hard to say for sure, but I think it has caused me more trouble than it has saved. Interested to hear other people's thoughts... pretty sure I know what @natefaubion thinks. 😉