I think 99% of the guys on here would be ethical in their use of a .223 in both distance and bullet selection.
Regulation are normally developed taking the worst case scenario or the lowest common denominator.
Look at the 45-70. SAAMI has the pressures really low to accommodate the trap door rifles. Even though 90% (or higher) of the 45-70 in use today could take much higher pressures. They need to set these low pressure so some idiot doesn't load a factory round in an old 45-70 and have a failure.
What happens when a guys uses a 40 grain Hornady Varmint Express, as opposed to a TSX? Unfortunately we are stuck abiding by the same rules designed to keep people from being idiots.