The problem is throughput. A satellite has a finite level of throughput, and that throughput is divided between all active users connected to it. In order to make that throughput work as well as possible for all subscribers using it, high speed data limits exist. Those limits require prioritization of online activities, especially bandwidth intensive ones like streaming. Removing those limits would result in the system becoming slower than molasses for everyone, as scores of subscribers would be trying stream. The system simply can't support that.
Data Tokens allow people to still engage in activities at higher speed after they've exhausted their normal allotment of high speed data, but it's meant as a temporary solution, and again, something prioritized.
Though it's a guess, streaming is eating through your data. HughesNet just isn't designed for regular, frequent streaming like people do with ground based services.
