Unlike Canada's two other highly reputable schools (U of T and McGill), Waterloo's reputation derives largely from the quality of its graduates over the last few decades, not from the fact that at one time they were the only university in their respective regions. Old money vs. new success. I say this as a U of T grad.

The McGill that earned McGill's reputation hasn't existed since people were going around in horse-drawn carriages.

Funny you should say that about McGill. I had some French colleagues who sent their kids there. I think the reputation is still intact overseas.

Your point also suggests that it takes more than reputation to thrive.