Wow. Yeah, that’s shady and shitty as hell. The cost was always enough to keep me away from them, but knowing they’re a shit company will make me sure to warn others off as well.
I do prefer the version where the bartender says “if you ask me again I’ll nail your feet to the bar!” Duck comes back in, asks “got any nails?” “No, why?” “Got any grapes?”
I would say if you accept subscription services as justifiable, Duolingo is justified. What you’re raising is poor performance, not a reason for it to be purchase only.
Of course, I would be in favor of “the app is free, pay a set price for a language pack” rather than a subscription for premium.