Apples and oranges.

West Lafayette is a true "college town" where a large public university dominates the local culture, but it is not nearly as nice as comparable places such as Bloomington, Iowa City, Ann Arbor, Chapel Hill, etc.

I don't think it's fair to compare WL or most college towns to South Bend, an industrial (or I guess post-industrial) city that happens to have a smaller private university nearby but outside the city limits. Even a famous, elite university such as ND will not have the effect on a town that a much larger school will have on a smaller town.

I personally like South Bend better than WL, but I have family roots in SB and have many reasons to dislike Purdue. Whichever is nicer, West Lafayette is more of an underachiever.