Hmm maybe it's just a European thing, you can typically fly most places in Europe/North Africa for for a couple of hundred dollars. Getting to the US isn't much more. Hotels on the other hand tend to be more expensive + hotel tax can be pricey.
And you do actually get the awful trade-off with planes in Europe as well, you get budget airlines like Ryan Air which many people don't travel on because they're so bad.
Ah yes, in the European context, where flights are cheaper and hotels more expensive (and extremely variable between richer and poorer parts of Europe), you could very well be right.
You can go from london to south east asia with AirAsia X for $500 and a decent midrange hotel costs around $20 to $30 a night. Also if your backpacking (hostels) or couchsurfing, it can be quite valuable.
And you do actually get the awful trade-off with planes in Europe as well, you get budget airlines like Ryan Air which many people don't travel on because they're so bad.