The biggest part of the stereotype is the lack of "normal" connectivity western Internet folks have with South Asian folk.

So often times the only time a western women is chatting with a South Asian man is when he is oddly in a group not commonly having many international folks, such as a US city subreddit, a US dating website, etc.

So the ESL, the forward disposition, the comical lewdness is all the more ridiculous due to how unexpected it is.

Also racism.