No no. To me, substantial would be 25%. I think that is a conservative estimate of the number of Dish subs who subscribe to, and chose Dish mainly for, International programming. Does that sound like a reasonable guesstimate? (Although, your guess of 33% is even more substantial.)
There is nothing wrong with it. And, it is an excellent business strategy. However, it also explains why Charles In Charge prefers to add Internationals instead of mainstream English language channels. Dish subs need to understand that.
That's why prospective subs who want the most sports and/or mainstream English-language arts and entertainment might do better to investigate DirecTV or their local Cableco's offerings before settling for Dish.