What does this have to do with the specific case here? I'm addressing an individual here on this forum, not some "average customer." The OP asked a specific question and I'm trying to provide a specific suggestion. What the "average" customer wants has nothing to do with this thread. If the OP didn't know about the Nexus 5, I'm letting her know. Unless you have a problem with me presenting that choice, I am not sure what your beef is.
That's false. You do NOT trade it in for no money in return. In fact, you trade it in for a specific sum: the sum equal to whatever is left on your device payments. If your device costs $600 and you have paid off $300 when you trade it in, you are trading it in for $300. The problem with the term 'lease' is that it implies a lack of choice. When you buy a phone on contract, you are free to keep it or trade it in if you want a new device. When you lease a car, you have to return it at the end of the lease period. The leaseholder also gets to dictate how you use a leased car (e.g. x number of miles per year, additional miles charged at y cents per mile), but when you buy a phone on installment, you determine how you use your phone. It's more a mortgage than a lease - except this doesn't cost interest.
Look, I understand that some find it better to pay a contract price and sign a contract. It may even make more sense for certain phones and plans - Verizon, for example, only takes $25 off for using EDGE, but for the top of the line devices, your monthly payment can exceed $30. If those are the devices you want, and you want to stay with your carrier for the foreseeable future, then it may well make sense for you to sign a contract. But this is why putting the cost of phones - at least as an option - is important for informed consumer choice. It may well lead to consumers deciding to purchase lower cost devices rather than devices pumped up with large marketing budgets.