Because the storage capacity would be limited, you can't add external HDDs for example and the other thing is it will have internet bandwidth costs as it will no longer have a dedicated pipe for the tv feed which means if the internet failed, so would the tv service. Currently, having a internet connection is not a requirement to view TV. Internet bandwidth may not be fast enough as it depends a lot on the routing on where it peers and if there is congestion latency on the many networks it connects through. All someone needs to do is send a DDoS attack on one or more networks between you and DISH and you will not have a usable internet service. or a Fiber Cut so basically any internet issue will also not allow you to watch tv as everything depends on that internet connection instead of the tv and internet each having dedicated individual connections. Some people may not be able to get Internet Service that meets the minimal requirements and some people have internet connections that are capped meaning a limited amount of data is included in what they pay before they have to pay additional for excess data to name a few things.
