In 2013, we face a world where management (rarely with competent training in anything other than not getting the company sued) blatantly plays favorites, "teams" sometimes turn on their strongest members, investment in junior peoples' careers is almost nonexistent, and firing is more likely to involve one of those humiliating, dishonest, and impossible "performance improvement plans" than a decent severance check. Imagine what high school would be like if the popular kids graded exams. That's what corporate work is like for most people.
If someone transfers through 5 colleges in 8 years before finally getting a degree, it's pretty clear that something unusual happened. That's a red flag. Colleges make a lot of effort not to be dysfunctional and to make evaluation fair, so it's a real warning sign if someone passes through 3 or 4 and can't succeed. Companies don't. They'd rather sacrifice fairness, decency, and protocol under the belief (perhaps mistaken?) that it makes them more efficient at delivering on projects. That volatile culture would be fine, if they weren't so stuck up about "job hoppers" in the hiring process.
We're not disloyal. We're just honest. Instead of sticking around and sabotaging a company that betrays us (out of fear of a job-hopper stigma, like what our parents faced) we leave. That's better for us and the companies.