Access to the hardware is not the point, it's the platform. Apps must be downloaded, updated, often using clunky and confusing embedded UIs made by the TV manufacturer. You have to input your email and a password to get access to the content. It's not as simple as plug in the TV, hit channel 849 and get ESPN. That's before you consider the payment, subscription, sufficient internet connection, etc.
Until it's as simple as that, it won't have the same broad appeal. For the mass-market consumer, one or more of the above things are a barrier to adopting streaming as an acceptable primary platform.