It depends on how you define rug in the first place. Because devs dumping their stake on the market, isn't the same as if they intentionally left a code vulnerability to be exploited in the future. It's unethical, but restricting devs from selling their stake is hard to regulate.

On the other hand, If malicious developers defraud investors by limiting sell orders then it becomes clear what they had in mind, hence, should be considered a crime.

Crypto is still a wild west industry, so being careful and doing proper research might help you reduce the potential harm.

Due Diligence is the king.