I have one of these (rebadged T221; ViewSonic VP2290b), got it second-hand in 2008 or 2009. It's not just the display connection bandwidth, the 41Hz and later-model 48Hz limit is from the display internals. They use huge custom FPGA logic chips to drive the signals, which are apparently not fast enough for more than that, although some of them can be overclocked to drive almost 60Hz. Without these internal display limitations, four DVI cables have enough bandwidth to run one at 60Hz (4x1920x1200@60Hz).
I haven't bothered to drive mine with four cables, because with just two (1920x2400) DVI signals I get it up to 34Hz, but I've scaled it down to 30Hz, because it's evenly divisible by 60Hz. In normal desktop use, it's fast enough. For gaming and movies, there are other displays.
Eventually there'll be a point in resolutions when it's bandwidth-wise better to have the GPU on the display side and just run some future thunderbolt-esque long cable than running even higher bandwidths to the display. An 8k display with a resolution of 7680x4320 would require 50Gbps of bandwidth to be driven at 60Hz at 8bpp or 60GHz at 10bpp. The actual required data rate between the CPU, RAM and GPU is much lower nowadays, especially because most of the heavy lifting like rendering and video decoding is done by the GPU.