Philly's rock station WMMR is getting good ratings, while NY can't support one. Their country station gets good ratings, but you saw how country did in NY. Philly is not comparable to NY.
I think Country did a lot better than expected. It may have not been seen in the city itself, but it did very well in the suburbs. Even in the city, it didn't have the lowest ratings. It lasted nearly 9 years which is a long time.
But regarding Soft Rock/Soft AC, it's not a bad idea and worth the try.