You have a point, there is a clear distinction the two, language acquisition and language learning, language learning like you have said seem to be more evolving and complicated due to the fact that people mostly involved are adults and they already had their first language which is their mother tongue. Some people needed to learn the new language because they find themselves changed environment which always requires them to communicate and they say good communication skills aids successfulness without communication they won't be much success since that is the key. Good insight, you have the point