Ok, you can think all you want.
You're wrong. I get to handle messed up issues where folks can't reach ipv4 sites on a fairly regular basis.
Our customers do not call the company of the website they're having a problem reaching. They call us. And when we find out that the problem isn't on our end, our folks have to get in touch with their provider, who will then either fix it (if it's their fault) or talk to their customer and get them to fix it.
If the big ISP's decided to take a 'you will use ipv6 only stance', then grandma would be mad at us if she couldn't read and post on her basketweaving forum.
Now, don't get me wrong, I'd love it if we'd be ballsy enough to make such a move. But the average end user is not understanding or reasonable. They expect their stuff to just work, and when it doesn't just work, they get mad at the people they're paying money to in order to make it work.
In a market that's saturated and the only growth comes from taking your competitors customers, we'd be handing our competitors a golden opportunity to stick it to us. I can see the ad campaigns now 'Comcast won't let you get to your basketweaving website? Come to AT&T! We have full internet connectivity!'