When a student applies to a college that put him on a wait list and he is never admitted to that college, it is not the end of the world. It may seem like it, but so long as that student applied to other similar colleges and was admitted to them, he can't lose.
Over decades of working with students and families on college admission, it has seemed to me that sometimes not getting in to a particular college can be a good thing. The reason that can be true is that sometimes students choose a college for the prestige factor rather than practical reasons. Not getting in to a particular college for which the student was qualified can mean going to another college that may be more nurturing and supportive.
A college that is more nurturing and supportive can translate into higher grades and better graduate school and job outcomes in the future.