jwidness also has some html / javascript that could be modified slightly to get stuff from the taxa API endpoint: https://github.com/jumear/stirfry/blob/master/iNat_Ungrafted_taxa.html.
here’s a simple wrapper page for the API endpoint, which won’t automatically iterate through pages (as the above code will), but it will allow you to view and page through results from the API a little easier (than just the raw json):
page: https://jumear.github.io/stirfry/iNatAPIv1_taxa.html
code: https://github.com/jumear/stirfry/blob/gh-pages/iNatAPIv1_taxa.html
note that the API won’t return more than 10,000 records for a given set of parameters, but you can work around that limit by setting id_above / id_below.
UPDATE: i added a little thing to the wrapper page to generate a csv file. like the rest of the page, it’s quick and dirty, but it should work well enough (though i’ve limited it to 10000 records for simplicity).