Whilst I agree with most of his sentiments about the game, my argument is simple: That's what you get from an Action RPG, which is what Borderlands and it's sequel are.
The Borderlands series is incredibly repetitive, time-consuming and nothing more than an item hunt game with the killing of bandits with numerous guns involved. It's much the same as the Diablo or the Torchlight games except that in those you're murdering foes with swords, not guns.
Action RPGs, in my opinion, are usually a "love it" or "hate it" thing. You either love grinding mercilessly for loot doing the same combat for hundreds of hours, or you don't. I love a game with captivating gameplay and storylines but sometimes, just being able to walk up to someone and blow their brains out for hours mindlessly is a fantastic stress relief.
Keep in mind that Yahtzee has already expressed some distaste in the entire genre when he's reviewed similar games, the earliest being Diablo 3.
Whilst Borderlands 2 definitely has it's downsides, it's still great in comparison to many of it's genre (I find it far more captivating than Diablo 3, for example) and in regards to shooting it's at least better than the majority of shooting games made today. AKA, Call of Duty and Battlefield.
Is it the "best game"? Hardly. Is it "Game of the Year" material? No, probably not. Does that make it a bad game? Only if you don't like mindlessly killing enemies with no real purpose, which some people don't.
And I'm fine with that.