I still don't see how the scoping is difficult. Since macros can see the whole structure and usage of symbols why can't it rename or insert/remove necessary de

I still don't see how the scoping is difficult. Since macros can see the whole structure and usage of symbols why can't it rename or insert/remove necessary declarations (eg local or set)? I can understand how each level of transmogrification makes things harder to grok but in general wouldn't there only be one level. eg if code was written for LispA and you are running LispB then you just need one level to fix that. (Sure if you are running LispC then you might need A -> B -> C but there aren't that many different Lisps listed!) My question still remains - what was it that made these Lisps so incompatible and couldn't be addressed using the existing much vaunted facilities already in the language?