Why do I say it is dishonest? Lets take an example.
Lets say I buy a house right this minute for $300,000 and everything progresses exactly as they say it should this means that in 2018 it'll be worth $600,000. I'll extend this out 60 years, pretending I'm 20 when I buy the place.
So lets say I'm 20 and buy a house for half the starting price I mention. When I retire the house by their calculation would be worth 3.4 million by the time I'm 60. If, with longer life spans, I don't retire until I'm 80, the house is worth $13.6 million. And that's in 2008 dollars!