Sounds like Nissan is trying to pull in more customers by copying Chrysler.
We bought the lifetime bumper-to-bumper on the new Caravan for a good price, would love to have had that on the Titan so I really could keep it forever.
On the mfr side, it's a numbers game. The lifetime warranties, in the case of Chrysler, aren't transferrable. Since most people only keep their vehicles for 5-7 years Chrysler ends up saving money over offering a standard 7/70 powertrain warranty that does transfer to a new owner.
The people that do keep their vehicles for longer will more than likely be repeat buyers, meaning they liked the vehicle SO much they kept it for 10-15 years, had repairs covered for that period, and are more than willing to buy another vehicle of the same make. Bingo, mfr wins again.
Where they lose is when someone keeps a vehicle for more than 7 years, has an excessive number of problems, and doesn't end up being a repeat buyer. The dealer is betting on those consumers to be the large minority.