Proposition: mark-up is always a bad idea.
His point seems to be that humans naturally translate texts, so that’s worth “computationalizing” (great word, BTW), but humans do not naturally POS tag, so why bother?
Okay, but is this false? Do humans naturally POS tag when processing language? I think it’s fair to say that humans naturally categorize natural language input, and some of this categorization could be likened to POS tagging. I’m going to need to brush up on my rusty psycholinguistics and make a more substantive post on this later.