1 Smartphone, pick your OS....Possible?

I'm no programmer and just your average tech savvy guy but I would love to see phone manufactures make kick as phones that people buy and then buy whichever OS they want and put it on their phone. So buy and HTC phone and then buy BB10 OS from BB to put on it. If you get tired of it but the hardware is still fine just buy iOS if that's what you want to try and load on it. Would something like this be possible? Carries would approve the OS and the consumer would just activate the phone through the carrier. Obviously, this is a very simplistic explanation and I'm sure there would be lots of issues to sort out but, good/bad idea......?

This would be a nightmare. Each OS would require lots of extra coding. You either have individual OS for each hardware or you have a big bloated OS to cover all. Android gets away with it because the hardware is built with the OS in mind. But its would be much harder to build that hardware for 4-6 different OS

It's not going to work as long as hardware makers differentiate on features. For example , the new iPhone will have a fingerprint sensor with a lot of OS integration that app developers can take advantage of to mostly eliminate logins. You're. to going to load some kind of generic OS that will take advantage of that anytime soon if ever.