Not to mention, there's a limit to plausibility even in a manga like Bleach. So when the sword stretches out, it'll essentially becomes trillions times heavier since the further away the weight is from the center of your body, the heavier and heavier an object gets. Since more than 99% the sword isn't even in his near vicinity, I can't even truly imagine how heavy the sword becomes.
Add in that he's cutting through hundreds or even thousands of buildings. And what if it was stuck inside buildings when he first extended it? The amount of strength needed to remove it then is unfathomable. I mean, if he's so strong, he should just throw large buildings at his opponents, it's FAR more practical.
And Ichigo blocked that? I call BS.