Funny thing is dofmaster comes to different conclusions: at 2 meters distance the 300/8 has a DOF of 0.12m, where the 50/1.0 would have only 0.09m. At a distance of 6 feet I get 0.33ft vs. 0.26ft. While the 50/1.0 may be a freak lens, a 50 F/1.2 is not, and is still comparable to the 300 F/8 on 8x10 cameras. And that's only at normal focal lengths. Once you compare a 200/2.0 or a 600F/4 to the lens lineup for MF/GF, you blow anything MF/GF out of the water.
The reason for this is not any inherent superiority of 35mm cameras. It's just that due to high market volume a lot more research effort is put into these small format lenses, providing us with insane lens designs. Look at the complexity in some of the newer 35mm lenses!