Welp, it's a good thing I said "I disagree, at least with what little was posted here" and "But if the vast majority of the vacation is already paid for, to the extent that there would be little/no money savings in staying home...."
Even if you're not that well off financially, if your vacation is 90% paid for, it may make sense to go even in the face of something like losing a job. A vacation to DisneyWorld is expensive; but if airfare, park tickets, hotel room, meal plan, etc. have already been paid for...why not go? The cost of staying home and buying groceries (plus higher electric/gas usage) would probably equal the negligible additional costs of going on the paid-for vacation (most of which could be eliminated, such as buying souvenirs). Of course, this assumes that most/all of the expenses are non-refundable; if you can get your hotel stay and airfare refunded, that changes the equation.
I just think we're too quick to jump to conclusions sometimes. A person losing their job and asking if it's ok to go on vacation, is not necessarily being stupid. Even if their finances aren't in the best of shape. Losing one's job, having no savings, being behind on basic bills, and asking if they should use a $5,000 tax refund on a Disney vacation or to pay some bills, should have the obvious answer pointed out (and anyone suggesting to go blow the $5k on a trip should be chastised). But I'm sure there's also plenty of people who have prepaid a lot of their trip (most of my vacation expenses are non-refundable, especially within weeks of the trip), and it's not such a clear-cut answer then. Perhaps they'd save $100 by not going on the paid-for trip; a trip that they spent many thousands of dollars on, that would bring a lot of enjoyment. Anything that's been prepaid and cannot be refunded should be looked at as a sunk cost. So that week of Disney isn't costing $5k...at the point of becoming unemployed it's going to cost $100. Even if it would in fact be better for them to not go, we're talking about a $100 mistake and not $5k (or whatever their actual numbers were).
Of course, it's entirely possible that this forum you speak of is in fact filled with nothing but people losing their jobs, then immediately booking an expensive vacation, even with foreclosure looming. If that's the case, then I agree with you wholeheartedly.