Why use such stupid and broken logic?
1. Ends do not justify the means. In theory, yes, if every single client was put in prison, then there would be no money for escorts and no money for pimps. That does not mean it is the correct solution, or even the most effective solution, for tackling the problem.
2. This law targets clients even when sex between the client and escort is fully consenting. It is unethical to have laws which criminalise people who are not doing anything wrong or immoral.