I think the author is claiming that the difficulty of undergraduate admissions is the important metric, not the quality of the program. UIUC and UT-Austin are tier 1 research departments, but not among the most selective of programs for undergraduates. (I realize they are extremely selective as PhD programs.)
@AznHisoka hit the nail on the head. It's ironic that the author missed the bigger picture of what his/her friend was trying to say when that was the point of his/her post.