Seems a weird argument to be making. You can't even pay them directly to get the Japanese version, you need a Shonen Jump subscription, but you want them to offer it for English speakers?
Relying on foreign distributors, especially when you need to translate, seems to make perfect sense to me. Should Oda provide translations into English, French, German, Korean, Chinese, and Vietnamese? All of those are part of the "audience outside of Japan".
Of those 1.5 Billion, how many speak it well enough to prefer to watch anime in it? I "speak" Spanish but I would never watch anime in Spanish because the cost of trying to comprehend translated Spanish is already too high for me to do it for casual entertainment.
Relying on foreign distributors, especially when you need to translate, seems to make perfect sense to me. Should Oda provide translations into English, French, German, Korean, Chinese, and Vietnamese? All of those are part of the "audience outside of Japan".