I agree, actually the only thing that is really necessary is an email address.
And even an Email address shouldn't necessarily be required. You can use token based surveys for surveys in field in on a tablet or in a central location project.
I usually would create tokens that are given out to interviewers, to have the possibility to restart where they left of if something went wrong with the questionnaire, and also to identify who did the interview. Then you have to put a bogus email address that actually will never be used.
Also, it would be great to be able to export a table with the individual links. Today you need to create your own links in Excel, but it should be easy to export the token links with the token table. But that is a different topic.