(1) Is the credentialing mechanism. BYU does not have the same cachet that a Harvard or a Yale has. Accordingly, the barrier to entry for some jobs will be much higher (or virtually impossible) as compared to someone with an Ivy League degree. 

(2) Is preparation/skills for work. I do think harder classes (if not harder just for the sake of being hard), do prepare you better for that. 

I think what most people mean when they say that BYU is an Ivy League education is that it prepares you well for jobs through training. I think that this is supported. See, e.g., below: