The real question is whether its worth going after the long tail if its an insignificant fraction of incoming immigrants (and really, an insignificant number in total). You have to consider that, in making sure the long tail is taken care of, you risk in making it significantly harder for the rest of the lot to make it through.
My experience has been that the long tail, in aggregate, form a large segment of the immigrant graduate population. I already stated this in my previous comment as statement A.
I narrated my experience, cited two links, and you go "that doesn't make reality, statistics say...". So I ask for said stats. What is amusing about that?
You then come back with an article titled "Estimates of the Unauthorized
Immigrant Population Residing in the
United States: January 2014", when the discussion here is about students gaming legal immigration. What relevance does that have to the topic, again?
You provided 2 news articles about 2 specific incidents. None of the news stories that you link to provide any indication whatsoever that students game the legal immigration system whatsoever. The document I cited gives specific numbers of authorized v/s unauthorized immigrants giving an idea of the scales we're talking about.
Its pretty clear that you've made up your mind about what the state of the world is (from various anecdata) and don't really care what the statistics really say. I will leave this as my last comment about this issue.