What I really objected to was the stereotyping. I know I'm not the only Indian who cares about punctuality.
Again, I object to the stereotyping. "You're on time. How American of you!"
(for the record, my personal perception of Indians is that they are quite punctual, because the Indians I've worked with were, and I didn't really have an opinion about it one way or another before that. Latin Americans on the other hand, let's just say that my experiences only reinforced the preexisting notions...)
That "oversimplified" is what makes it an unreasonable assumption.
My point was coming from a slightly different notion of 'stereotype' where it's more similar to 'preconceived notion'. Maybe it's just a language thing.
What I'm objecting to is what I have explained I mean by the word in the context of the original assertion by elbenshira, viz. that regard for punctuality is predominantly an American/Western trait.
And if you don't mind, this is all I have to say about it.