I’m struggling to remember a time when WDW was considered an “affordable” family vacation. Sure it may have been “more” affordable than it is now, but there’s still ways to do Disney cheap - stay off property, don’t eat at the resorts, don’t buy souvenirs or extras, etc.WDW used to be an affordable family vacation. Europe has always been an expensive trip. Now people look at the cost of WDW and think "WOW" the places I could go with that money. Then you think why am I spending a ridiculous amount of money for a theme park vacation when I could actually go to some of the places in Epcot.
Also, Europe is cheap right now because of a weak Euro. Not that it’s a bad idea to travel there when their currency is weak, but generally a strong dollar vs a weak Euro will make the disparity between a US luxury “once in a lifetime” vacation look even more expensive international one - especially when the deciding factor is flight cost.