Though your intention appers good to have a united populace of India, the reasoning is biased Also it lacks the overall view. Let me elaborate:
Any local party like ShivSena, be it AIDMK or DMK or whatever elsewhere could survive ONLY if they have the support first from the localities. If they loose it, they would loose the strength. ShivSena in recent past is moving away from Marathis & hence loosing support. But it doesn't men they can't control Maharashtra, let alone Mumbai. It's the people of local people of Maharashtra, aka Marathis, who need to do it.
You've correct in saying that there're businesses all over India. Add to it that either small or large scale. But is there any such variety of businesses being run?
Don't even compare B'lore or Madras with Mumbai. It's impossible. The localities in those cities never mix & allow others to even speak Hindi or respond positively to their views. Would the same happen in Mumbai? No, the people of Maharashtra are too humble & polite. They go beyond what they need to do to welcome an outsider, stranger.
It appears that your knowledge of politics & overall economy is weak. Every state government depends heavily on Central Government. That's why we have a budget with billions of losses. The point here is the other states have adequate representation in assembly & they unite to fight for the rights of their state. The lazy Marathi politicians fight among themselves & hence Maharashtra is deprived of Central Govt funds..
