I would argue that "failing" to interpret sarcasm in this context is generally the fault of the person employing sarcasm. With none of the other cues that are available IRL (tone of voice, body language, facial expression, etc.) there's very little to tell a reader what is meant to be taken literally, versus taken as sarcasm. So yeah, if a writer doesn't include /s or ⸮ or whatever, that's on them if their words are misunderstood.