People hating the 8-bit limit has little to do with displaying colors on your monitor, unless they are just parroting. The 8-bit limit comes into play when it comes to _processing_ your images.
You can see it any time you want with Gimp if you play around with multiple layers and run a few filters. Before long you'll start seeing visual artifacts start showing up. Colors that are wrong, weird L-shaped artifacts, lots of graininess, and errors that look like the sort of things you get from highly compressed jpeg images.
One of the nice things about digital art is the ability to twist and deconstruct images to make new images. Like how you can take audio samples of every day things, manipulate them, and make music out of things.
With just 8-bits then this makes the process a lot more time consuming, depending on what your aiming for.