Answer to your question lies your very post. The same Indians who probably cheat on taxes in every possible way in India(Fake rent receipts, Opting to buy things without a bill, show wrong records for accounting purposes), break every single traffic rule, litter streets, spit on the roads, break building regulations, play politics at office places, indulge in linguistic, regional and religious politics and do nearly everything wrong India; after arriving in U.S tend to exact opposite.

Why is that so? Life in the U.S doesn't come for free either. Account for all your taxes, expenses and cost of living and you will see this is simply trading one thing for the other.