Fair enough. I consider every action in this game a grind, but I'm using the term in a less negative way. Either way, this thread went off topic after the 1st response.
I just want to know why everyone keeps on the grind. Why do we continue to play?
OK, I'll play along and assume you're not trolling and are ernestly asking a question. Any game can be reduced to your "less negative" definition of grind. For example, people have been telling me how great Borderlands 2 is. My friend finally gifted me a copy on Steam a week ago and I've played to level 5. So far, it is a grind, by your definition. Sure, there's a funny robot and some funny NPC dialogs, but at the end of the day, it's take mission, go somewhere, shoot some stuff, return, get reward, rinse, repeat.
So, why do I play? Because it's fun. It's the same reason I play World of Tanks (start a battle, move forward, shoot other tanks, die maybe, rinse, repeat). It's the same reason I play Elite Dangerous. I play because I enjoy the gameplay elements. I play because it's fun.