All these schools (including ones you describe as “not-so” selective) are very, very, very selective.
They attract top students from all over the world.
And yes, some of these schools limit the number of international students to under 10-15%. You don’t specify if he was seeking financial aid – at many schools, that puts the applicant at an additional disadvantage.
The reality is that applying to most of these these schools is like playing the lottery.