There's nothing about 720p that's intrinsically blurry or pixelated. That's just something a lot of fixed pixel displays do to the image while upscaling. If you have a 720p monitor you could still get a crisp, clean 720p image on it. CRTs are even more resolution agnostic, because they create an analog representation of the image rather than a digital one. A lower resolution image will often be less detailed on a CRT, but you don't see the type of aliasing you would get on a fixed pixel display.
You need high framerates to eliminate motion judder, which can actually degrade sharpness and detail in motion even more than a lower resolution would.