MH has two backward regions, though they are different in their origins and aspirations:
Vidarbha is from erstwhile Central Province, in fact Nagpur was the capital of Central Province, Vidarbha statehood proponents claim that Nagpur was better off then, because it attracted investments as a state capital, and that Western Maharashtrians are treating Vidarbha like crap.
Marathwada is from erstwhile Hyderabad State. Even today, people of Marathwada have many family links with Telangana and NE-Karnataka, though they don't regret being split from Hyderabad. The Nizam of Hyderabad was an arsewhole, and treated Marathwada like crap (far worse than he treated Telangana). Maharashtra has invested fairly well in Marthwada, although it's still a backward region. Though Marathwada still has many anthropological links with Telangana. One stroll across Kachiguda and old-Koti, and you'll find countless Marathi families from the Marathwada region.