This is fair. However, I think the situation the OP is complaining about is not one application that does structured logging (where I agree with you that even i

This is fair. However, I think the situation the OP is complaining about is not one application that does structured logging (where I agree with you that even if the data is "plain text" in some sense, it's not terribly productive to think of it as plain text), but instead about a system log that many unrelated applications write to. Each of those applications has their own way of structuring their logs: there is no standard. Hence you end up with something that is technically plain text, but also really nothing more because there is no consistent structure. So it's really just plain text.