This 'punishing' is a natural result of video taking most of the internet bandwidth. It's easy for companies to sell 'unlimited' something when the expected use is low, but when usage is high, that becomes impractical.
Logically if you use 300GB a month, you should pay 300 times higher than someone who uses 1GB. That won't sell too well, so that's not what happens, but you should keep that at the back of your mind. You're using a limited resource. With cable, that infrastructure is factored into the payment. With the internet, it needs to be factored somewhere, so there's every reason for the provider to limit you or charge more.
Logically if you use 300GB a month, you should pay 300 times higher than someone who uses 1GB. That won't sell too well, so that's not what happens, but you should keep that at the back of your mind. You're using a limited resource. With cable, that infrastructure is factored into the payment. With the internet, it needs to be factored somewhere, so there's every reason for the provider to limit you or charge more.