What am I missing here? What's the difference between this guy, and all the people within earshot of this forum that you don't even know, but have been "counseling" against going into aviation?

What it tells me is that every individual's situation is different and that even you recognize that. So, instead of making blanket assertions that nobody should ever consider a career in aviation for any reason, perhaps you could, in light of the fact that you seem to enjoy hanging out with people who have an affection for aviation, be more supportive of one's aviation goals. With your supposed experience, you could help to guide people around the pitfalls, instead of just broadly trying to forbid people from considering it at all.