I'm curious as to why neither the Cadillac line nor the Michigan/Woodward lines extend up into the Pointes, yet St. Claire Shores has a major hub. Grosse Pointe

I'm curious as to why neither the Cadillac line nor the Michigan/Woodward lines extend up into the Pointes, yet St. Claire Shores has a major hub. Grosse Pointe Park in particular is quite walkable, especially in the older areas that were build primarily for house servants.