Talking about obviousness as if it was inherent in a conclusion is typical mind projection fallacy. What it generally implies (and what I think you mean) is that any sufficiently rational person would see it; but when lots of people don't see it, calling it obvious is against social convention (it's claiming higher rationality and thus social status than your audience). In this case I think that to your average reader the analogies aren't obviously irrelevant, even though I personally do find them obviously irrelevant.