The idea about unlocking is so you can easily go to another carrier if you want to, without replacing your phone.
What other reason would you need for having an unlocked phone?
It's not about how often you change carriers, it's about the versatility to buy a phone when you need it, where you find it, and use it on a different carrier if you prefer it for whatever reason.
You don't have that convenience with a locked phone, without paying for it, and... you pay more to do it. No way can you prove otherwise.
Did you choose to forget the "24-months" part of the financing?
An unlocked phone may be the same per month, but you don't have a 24 month contract, either. Because - you own the phone, no contract, and you can do what you want with it from month to month, not locked in to the carrier...
...
oh, crap... Am I really talking in circles here? Now I know what that dog feels like out chasing his tail....
To the other folks who unfortunately, like me, got sucked in to this thread:
More than 45 posts for the troll. I guess you can count that as successful trolling

. (if there is such a thing)