Well i found your conclusion unreasonable and immature. How many who entered in f1 visa remain in f1...eventually they will turn to h1b and greencard. its obvious. Also there are many persons whose siblings now reside in US. Even in USembassy webchat regarding f1 visa ..they say about siblings residing in US that the student needs to provide enough ties to the country.  Simply because i had green card doesnot prove my brothers intend to immigrate, it creates the suspicion which is absolutely dependant on the mood of the consular. My expectation from the sajha community was....how can we convince the intent to return and not immigrate.  FYI when i was a student. one of my roomate brother was the US citizen here...who entered US as a student and married to US citizen later. This was not obstruction for him. But again it was 7 years ago...and i donot want to create an argument.