Thanks for bringing this up. I agree with you that letting users ask for credit is a great idea, but it may not always be what someone wants. Perhaps we could have just 2 options - CC0 or CC-BY, and let people choose it by saying
[x] I want to be credited for this dataset.
We will have to investigate a little about what a derivative work is. If someone makes a model using a dataset licensed under CC-BY, I don't know where the citation requirements come in.