I disapprove of other people’s choices only when it negatively impacts the life of others. If sex work is legal and regulated and taxed and there is a robust social safety net, then all that’s left to disapprove of is the sex itself, which is for religious zealots, not normal people. Sex is a drive honed over hundreds of millions of years, there is literally nothing more normal.
If it has been made illegal, then I may disapprove of the laws which make it illegal (ie: we don’t disapprove of anti-trafficking laws), but if such laws are in place, I cannot approve of the illegal work, because unsavory shit comes along with it that negatively impacts other people.