Re: Really?
My point was that the change isn't a switch on the web UI. It's not a line in a config file. In many cases, it's a kernel code change, which isn't that many lines of code but still requires recompiling the kernel and pushing out that update. Most devices that ISPs provide don't get new kernels from them. New kernels come from the manufacturer who has forgotten all about these boxes years ago. In many cases, the update files don't even change the kernel, just the configs and libraries, making applying kernel updates a more involved process.
There are some other devices which have separate hardware for routing which may have that rule coded in, and in that case, the change is bigger. Again, not that many lines of code to remove the logic, but a lot of stages required to get someone to make that change and get it installed on all the equipment in which that hardware exists. If you think ISPs have the ability to simply make any change of this magnitude, I'm surprised to see you constantly annoyed at IPV6; all they'd have to do is push a kernel version with the existing IPV6 support turned on, after all. That is a lot of work too, but at least a lot of it has already been done. When my ISP didn't offer IPV6, their hardware (optional) had the support. They just didn't give out addresses. Now, they do support it and most modern routers, including their pre-switch hardware, will just connect and use that.