You make a good point. However, this isn't universal. First of all, as the proverbial fat guy at an all-you-can-eat buffet, I've already chosen pay a higher price for significantly more bandwidth than my neighbors. I have an expectation that I have full access to that. I am also lucky enough to have a choice in ISP's where I live. I cancelled my capped service for a more expensive (and even faster) uncapped service. It's not a hard-and-fast rule, but I'm willing to pay more for a bigger plate - I just don't want to be gouged by my ISP for that plate. I'm not saying that they can't say "no" to that either - it's their network. I just know what I want as a consumer, and my hope is that I live in a place where competition is great enough that I have that choice.
Another thing that is rapidly changing is the ease of access to streaming for the masses. It used to be that only geeks like me would build a dedicated media PC tied to a TV for streaming video. Now, streaming appliances are ubiquitous. Streaming for Netflix (and related services) is available on dedicated devices (like a Roku) for $100. It's built into TiVo, and it's even integrated into most TV's and Blu Ray players. My parents stream internet video, and they're in their 70's. If that isn't a litmus test for the masses streaming internet video, I don't know what is.
The other thing that you mention is that the vast majority of ISP's do not offer any TV service at all. I am not sure where you're getting your numbers on this (and it could be that you're talking about the amount of ISP's versus the amount of subscribers). I presume that you're referring to residential broadband internet. Most Americans choose between Cable and DSL, and some can get FTTH. According to this report, as of late 2013, over 50% of American residential broadband internet is delivered via Cable. DSL is at 34% and is trending downward. I'm not trying to get into a pissing match here, as you make a good point, but what I'm saying is that most customers purchase internet connectivity from providers who do sell TV service. Given this information, it's no surprise that it's not in the best interest of the largest type of ISP to be entirely friendly to streaming video service. This is even more poignant given that the cable and FTTH providers are all trying to sell their own competing streaming service to us. Finally, remember that the AOL/Time Warner merger, while an utter failure, was (in large part) supposed to merge internet and video service to dominate the VOD marketplace. Again, it didn't work, but this has been on the mind of big companies for a very long time.
I'm not arguing against what you suggested that I'm the fat guy at an all-you-can-eat buffet. I totally am that guy. But things are changing. The average consumer is streaming internet video, and the whole content industry is shifting in that direction (e.g. 95% of the HBO-produced shows will shortly become available on Amazon Prime Instant Video). The writing is on the wall, and many of these companies are trying to milk returns from their legacy investments for as long as they can. I can't fault them for it, as these are expensive networks to build and maintain. However, they need to tread lightly, because given the lack of competition in most marketplaces, anything viewed as abuse will make these ISP's ripe targets for federal regulation.