Should undergraduate students be included on papers containing data they collected?
A few comments:


Were they asked to contribute to the paper or was the paper written without their knowledge? If they refused to contribute, then they shouldn't be a named author. If they weren't asked, then it's not their fault they didn't contribute ;)
I think the word undergraduate is a red herring. Substitute it with the word PhD student or RA or Prof from the lab next door, does this change your view? A person's title shouldn't influence their inclusion.
How much work are we talking about here? When I provide statistical advice, I'm happy to give up a few hours of my time for free. But once I'm spending days on the project, then I expect (and make it clear) to be am named author. 
If data collection was "trivial", then I would suggest it shouldn't be used as an undergraduate project. Also, I presume that there was some skill in collecting the data?