Yes, it can be useful because understanding motivation can be a great tool for outreach and for editor retention.  You can compare the list of motivations as to why people contribute versus why people fail to contribute. There often appears a great big disconnect between the list, and I have not seen much evidence to suggest that people have explored this.

Why is it that some people contribute because think free sharing of knowledge is an important activity to engage in in their free time? But others do not contribute because they think the editor is too complex?  Perhaps, the motivation to overcome the editing problems is higher for some populations than others... because one set is willing to do that and it is a non-issue but for another, it is a non-starter.