The 'both people are a risk of PK' is the balancing aspect to allow mugging to occur but the reality is that someone can effectively make a fresh char, get a gun (or be provided one) and mug with literally no risk. Whereas the victim is a character with 500+ hours.
Every situation is different or nuanced (obviously if you think staff is being biased make a staff report) but no 'revamping' would make it work in a way that would fix the issues (we would have done it) or it would turn it into dark RP mugs with no consequence. /advert mug move or die.
The only possible changed I'v toyed with is potentially making mugging a criminal only act, meaning you must be in a crime family to mug someone, but this doesn't really stop alt chars and may encourage certain factions to be mug only faccs (which is good or bad depending on your perspective)
Your suggestion isn't even a suggestion, it provides no new ideas or alternatives, you said "this sucks fix it" without any solutions.