I think the problem with this view is that academic linguistics has a limited amount of useful information to tell people who are trying to learn a language. Ab

I think the problem with this view is that academic linguistics has a limited amount of useful information to tell people who are trying to learn a language. Absolutely people learning a language need informed linguistic advice. And our understanding of language learning is much less rudimentary than it used to be. But linguistics is a multidisciplinary, multiparadigmatic field in which there is serious disagreement over some very basic questions. Dost of the good language apps definitely include that. But a lot of language learning is about keeping up motivation and finding ways to access and practice the target language more often, to bring down the barriers to using and communicating in the language. Good software tools can help there, because we can't all afford personal tutors at $30/hour.