Tech schools like RPI can appeal to those students who really want a school that is more singularly directed in tech and the sciences. I knew students who felt they finally found a place for themselves when they arrived at schools like RPI, MIT, Harvey Mudd, Cal Tech, Stevens, etc. They found a larger core of people like themselves with similar interests. Some of them had suffered terribly in highschool because they did not fit into the mainstream culture and these school provided a haven of sorts to them.
There can also be a camaraderie to get through the intense curriculums these schools have, when there are so many students all on the same track. With those schools that have a large variety of offerings, it can be a distraction, temptation, problem to be in the other courses of study, taking those courses with the same sort of students and issues that were problematic.
These schools, however, are rigorous and have a type of culture that is not for everyone. And if you don’t do well at college, your transfer options can be limited Schools like RPI often have steep grading curves. Non tech majors may still not meet the desires of some students who really want out of the environment and into a more mainstream general education type school.