Earlier quoted context omitted.
Pretty much all non-native speakers who want to learn English that I've ever met do want to learn American English specifically, particularly those who want to work in America. (I prefer South African English, personally, but I think the commercial market is strongly in favor of American English.)
"Your anecdotal evidence is wrong - I want the opposite" "No, your anecdotal evidence is wrong." "My anecdotal evidence is right."
(A totally fluent UK/IE/etc English speaker probably is fine in any context, but I don't think someone learning from a webapp is starting from that point. If you are going to be a moderate speaker, it is better to be moderate in the target accent.)