Co-op wasn’t one of the main things that drew me to Northeastern (I was planning to graduate in 3-4 years and maybe do a co-op), but I ended up really loving that part of it and did the full 5 years and 3 co-ops. So I chose Northeastern for many reasons besides just co-op. A big factor was the full-tuition scholarship. Plus I liked Boston and the campus (and wanted a change of pace from small-town midwest). Despite being a large research university, it still seemed to really have a focus on undergraduates that I didn’t feel at a lot of other big institutions. That’s played out in my experience here, too: my professors know me and I’ve gotten great individualized research experiences.
I have had friends do 1, 2, or 3 co-ops, and I know of 1 or 2 people who haven’t done co-ops. I probably know other people who haven’t gone on co-op, but if they haven’t it just doesn’t come up. It’s not like all your classmates are tallying up your co-ops. It’s a very individualized experience. Most (if not all) majors that don’t explicitly require a co-op do require some sort of experiential education, but this can come in a variety of forms, like directed study, honors thesis, or co-op. A lot of people end up doing more than one of those options, I think.