A “wrap” is the generic term for food wrapped in something vaguely large-tortilla-like. Just because people somewhere call something a burrito doesn’t make it true.
You are just flat wrong here. The world clearly agrees that burritos can have beans and pizza can have pineapples. If you try to limit the meaning of "burrito" you are simply not accurately conveying what the word means. In addition "traditional burritos" have long included a wide variety of ingredients, including beans, though usually not with as many ingredients per burrito as a "mission burrito".