I am from Kerala, not a marathi or a bhaiyya, so I can be unbiased here. I lived in Bombay for two years in the late 90s. And here're my observations:
1. The contribution of Marathis to the development of Bombay is miniscule, other than naming all buildings in Bombay as Shivaji. Bollywood is primarily punjabi. Business is primarily Gujju/Marwari/Kannadiga. Software/IT dominated by southerners. Most of the restarants are either punjsbi or udupi. The Marathis are found in givernments jobs. In fact my only interaction with Marathis were with bus conductors and the house-maid.
2. The bhaiyyas make 90% os the slum population in India. There live in shanty homes in the most unhygienic conditions. Moring office commuters have to see thier unhygienic actions enriute to thier office everyday. International visitors see this too. During rains all this filth make s Bombay one big filty pond.
To conclude, I agree with Raj. He is not against immigrants who have a good job and live in respectable conditions. He is against Bombay being flooded wit relatives of Lalu and Mulayam who bring unhygiene, filth and crime to Bombay