This is the argument I use again people using the "it's fine for now" argument for Australia having replaced the gigabit fibre-to-the-home plan with an equally expensive 25Mbit Fibre-to-the-node plan to save a whopping one year on construction time.
Sure, most people can live with 25Mbit now, but what about in five years? Ten? Twenty?
We don't need to argue. You just agreed with us.
Comcast haven't said they'll never change this policy or offer greater plans. They're offering plans that reflect the current marketplace, not doing so is bad business.
In addition to that, if you read the article you'll see you can still get 100% unlimited Internet for $200/mo. They're simply asking their high-demand customers to pay in such a way that reflects what it costs to provide for those customers.
I don't walk into a restaurant and expect a flat price for my meal that's the same as every one else... err, unless it's an all-you-can-eat... and they charge for drinks!
You're paying for peak performance, not 24/7 performance.
I do understand, though, that by having a data cap they're encouraging users to use less of that bandwidth. However, again, they're just passing on costs to the consumer instead of paying a fixed cost to upgrade their peering arrangements.
Isn't a "link of speed X" exactly how it works everywhere outside of the overselling done by last mile monopolists?