It seems unreasonably idealistic to hope that all displays would ship calibrated to any standard. However, sRGB in particular would be a very limiting choice since it is a rather restricted space.
It's okay as a fallback "safety", but by design it's a lowest-common-factor. Restricting all hardware to that would keep us from taking advantage of better hardware and getting the most out of new display technology.
By working with a color-calibrated device in the first place and using a color-managed workflow, you can take advantage of better hardware and be reasonably certain that the images you create will render decently on a "non-broken" default-sRGB device.