Categorising something as either singular/plural is not always a clear cut decision. Many words can be treated as singular OR as plural. I think that some examples of these are: generation, family, government, range, and variety.
e.g. - A variety (of protest groups) were/was gathering on the foreshore.
A range (of scores) were/was recorded in the record books.
The government were/was adamant about imposing new legislation.
The family were/was so happy about the new car they had just bought.
Their generation do/does not wear shoes.
In each of the above examples, I think that either form (plural/singular) of the auxiliary verb is acceptable.
I think that, "Their generation do not wear shoes" should be accepted as a correct answer.