I actually agree with you post and view, however, this is sorta along the same "avoid Starbucks and invest the $5 per day in an IRA and see how much is grows" The issue is delayed gratification and that is not something Americans do very well.
Sure if you can pay cash and you love Disney and plan to use
DVC for 7-10 years then it is a very sound financial purchase. That does not mean financing at 5% is bad either, however, anyone that finances any timeshare with minimal down payment and gets 10% or more interest rates is making a mistake.
Also, if people really want to join DVC and have limited funds, then buy a 25 to 50 point contract in cash and transfer in points from other members as a rental.