Bandwidth costs money. So consumer "ISPs" (and I use that term in a very loose sense) tell you what the burst bandwidth is, and then hope that you don't burst very often. When you do, they drop you, because you cost them money. The solution is to just get a real Internet connection. "Business" is the magic word.
The alternative to Comcast's cap strategy is that everyone would be paying $500 a month for Internet access, or you'd be limited to 768kbps with no burst.