In my experience, his third point (on them trying harder, and thus being more willing to treat ethical boundaries in an elastic manner) is spot-on.
Another indicator that this is true is that he says that being on a work visa required his colleagues to push ethical boundaries. Having worked for many years, multiple employers and many managers on a work visa myself, I can assure you that this is not true everywhere, or even most places.
Seriously, any one on a work visa who is being pressured to do something ethically repugnant should change their job. In many cases this is easier than you would imagine.
But yeah it might be very different on the west coast.
And your wrong its not easy to change a work visa because you lose your line in the G.C race if your not in the 3rd stage. Thats the clincher.
With present EB3 approval rates, its possible this could set you back 5 years. EB3 India is a mess right now.
What he meant, I rather suspect, is not so much as 'ethically repugnant' (in which case I might agree with you) but rather within the gray area, where unvoiced pressures such as these can affect the choices you make.
My friends and I have had many many managers and a good many were indian. Only one of them I would rate as good. Funnily enough I used to be his manager a long time ago. I've actually learnt a lot from his style of leadership though I've never worked under him.
He (ie 1) is the exception who IMHO proves the rule.