Is there a reason these doomsday scenarios didn't happen prior to the current regs?
I am going to venture that if we only hopped back 10-15 years ago the internet wasn't as ubiquitous of an item compared to the sales and money and traffic it has now. I am just guessing that a provider like Time Warner sat there and was like "yeah, we make all our $$ on cable, internet is a nice bump" and when people didn't want cable anymore and you could stream shows, movies, etc over the internet, the ball game changed. I mean, you have to remember something like Netflix was a mailing DVD service at first, and it was that not because they loved DVDs but because it was incapable of providing streaming service with 2007 internet for most people.
Basically, you couldn't do on the internet then what you can now, so tiering it would've been more of a why bother, rather than a why not. I hope you get that 125kB email 0.5 seconds faster.