Because during The Fame Monster era, her music was smart enough for music critics to nod their heads and approve of it. While the GP approved of the new sound she was giving off. The writing, the production, the cohesive album and her way to be different enough without being in your face about it. It was mostly High Fashion, not weird.
Since BTW, she started feeling herself too much, and her videos kept getting stranger, just to be strange. With ARTPOP, its back to shallow lyrics (sans a few songs) and even weirder antics and desperate please for attention. She didn't know when to stop.