I do not understand motion blur. I am paying top dollar for these pixels, let me see them all. That it is a negative performance impact makes my decision all the easier.
Even in the 90s, the developers of 3D arcade racing games were well aware of this, ensuring that the original arcade versions of games like Ridge Racer, Daytona, and Sega Rally ran at 60fps, rather than sacrificing that smoothness to add more detail. And those games looked spectacularly good for their time.