Because it always worked on X11 and Mint Cinnamon is just that. I used NVIDIA graphics on X11 in 2007 and, apart from the extra dkms driver that could break at times, it was fine, and much better anyway than ATI/AMD with proprietary fglrx driver. Rest in piss son of a bitch.
The question was what would I recommend for Wayland. Only the brand new 555 driver combined with most recent compositors (and other packages like mesa, xwayland,…) offers decent NVIDIA experience. It’s a matter of new distro releases around this fall.