Ok, this would need a huge amount of infrastructure.
BUT!
I'd like for normal people to be able to call me at my computer/OR skype hardware device!
I don't care what rates you have, I don't call that much... But I need a phone!
Now, TELIA in Sweden takes 375 SEK every quarter from me, just because I have a landline. I pay the minute bill to another company, usually around 40 SEK.
Get my point?