I don't think it's irreconcilable I just think formal language is, in many cases, a detriment to itself. The goal of language and the goal of learning to to create a pool of shared meaning. Through that pool of shared meaning we can bond and grow as a group. The formal language used in "essay english" is often only used because "that's how essay's are supposed to sound". The goal of the information shifts from trying to share knowledge to trying to sound right - the latter helps no one. Formal language has a stigma of "if you don't understand this, then you are dumb" which usually makes people who don't understand feel unsafe. You can create a dialogue in any language so long as every participant feels safe - so you could have a dialogue in formal language, as long as you make sure everyone understands the language while you're talking.
Good point. There's a place for any kind of language and a time to use it. Academic speech belongs in academia, and slang belongs in the group of origin.you could have a dialogue in formal language, as long as you make sure everyone understands the language while you're talking.