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.
The delicious irony is that they now get to live in the world they helped create.