It’s a bar that every Duolingo user is hopping over while a bunch of procrastinators are making excuses about why they haven’t started yet.

Duolingo is not a complete solution and I don’t think they or anyone else claims that it is. What it solves fantastically well is the zero-to-habit transition.

Yeah, that's a ridiculously low bar for something that costs like $150/year, for that matter.