Why is a fumble through the endzone a touchback?

Answer 1

This is a good question. Unfortunately, there is no good answer other than that's the way the rule was written. Presumably, if a defense is good enough to cause a fumble in the endzone, they are rewarded. However, it doesn't make much sense, as anywhere else on the field, a fumble out of bounds is retained by the team with the ball in the first place. I personally think it's a dumb rule, but that's the way the rule was drafted.

Answer 2

that would be called a touchdown