Colleges with different institutional needs will often focus on different parts of a kid’s application. A large public university will look mostly at the stats and course list, while a LAC will focus a lot more on the ECs. A student with an academic profile that fits a large public university will often also have an EC profile which is attractive to some LACs. These are not mutually exclusive. The same way in which a kid will find parts of each college which they like, a college will look at the parts of a kid’s application which they find important, and make their decisions based on that.
Also, students will tailor the essays and certain parts of their application based on the college to which they are applying. My kid’s essay for UIUC and UMN were not the one she used on her LAC application. In many ways, the large public research university, the smaller private research university, and the liberal arts college are not really looking at the same kid, or at least, they are looking at very different aspects of the kid.
Of course, the kid may be mistaken, but then again, so can the college. Admissions people are not omniscient. They only know of a student what the student wants to share. If what the kid shares looks good, they’ll accept the kid, without checking any more deeply whether the kid is TRULY a “fit”.
Admissions people in a wide array of colleges may look at a kid with top grades, an impressive list of awards, and a well crafted essay, and say “we want that kid”, without looking too deeply into whether the kid fits into the college, personality wise. It is the same way many kids and parents will apply to, and automatically accept an offer from, a high prestige school, based on prestige alone, even if it’s not really the best fit for the kid.
So kids often apply and are accepted into many types of colleges because they can fit into many types of colleges, and colleges often accept kids who would also fit in many other types of college. This, I think, is what is usually happening. Sometimes, though, kids will be “blinded” to issues of fit by the prestige of a college, and sometimes admissions people will be blinded to issues of fit because of an applicants impressive array of awards, or their fame. However, even in those cases, kids are generally resilient enough and adaptive enough, that they will mange to do well anywhere they end up, and colleges will often put some effort into helping students find their place in the college…