If by "this domain" you mean "strong type-checking", I guess it is because the CL's feature of on the fly introspection/debugging/modification is not as emphasized in some static type-checking languages, the lack of compile-time strong type-checking feature in CL, the ease to modify CL's compiler behavior via macros/reader-macros/compiler-macros (which facilitates implementing compile-time features like strong type-checking at compile-time); and perhaps also due to CL having been used in language research and in production for some decades.