While Markov chains involve probabilistic transitions and may seem random at a glance, they do follow specific rules and probabilities. They're not inherently incoherent or illogical; they just operate under a different kind of logic that's based on probability rather than deterministic cause and effect.
Comparing human communication to a mathematical model like a Markov chain is a bit of a stretch. Human speech, even when it seems disorganized, usually has more context and underlying intent than the transitions in a Markov chain.