There is a locked thread on your GitHub page for your web API dealing with this issue:
It is locked, because too many people added their +1 comment to it, not because it was considered as unnecessary. So I think it makes sense to create an idea for it on this forum, so more interested users could vote for it. Offering API access to a Spotify user's listening history would enable external developers to create statistic tools or e.g. export it to Last.fm.
Updated on 2018-01-30
Your idea has been submitted a while ago but unfortunately hasn't gathered enough kudos (50 per year). In order to keep an overview of the active & recent ideas in this forum, we will have to close this idea for now. However, this does not mean that your idea has been rejected by Spotify.
If you still feel strongly about your request, we encourage you to post your idea again, in a slightly different form! Maybe now is the right time to receive the support of the community for your suggestion! ;)
Do you have any further questions on how the idea exchange is managed? Just click here!