I believe the argument isn't that it was unreasonable, it's that there's a moment that had the potential to be really awesome, showing just how much training Sasuke had been putting in after his team's failure to protect Tazuna (and if you don't think Sasuke would push himself to the brink after what he would see as a failure that big, you're crazy), and Matt simply denied the reader's that fight. It could have been something as cool as the Valley of the End fight in canon, instead, we don't see much of anything. I know that it is in character for Naruto to try and finish Sasuke as fast as possible, and I thought it was cool as hell. However, I can see where people come from when people say that it's an awful moment, as they wanted to see a fight between Naruto and Sasuke that doesn't involve Kyuubi chakra or the curse seal. It's all subjective.
MrRigger