That's like saying you are against Islam but support Muslims or against art but support painters. 
Erm...what?
I support sex workers. I support their rights and want better for them. I do not support sex work due to the many issues within it and the platforms promoting exploitation. Just as I can support the rights of low paid Mcdonald's workers without supporting Mcdonald's.
But you don't support their right to do sex work which is the thing that makes them sex workers.
If they didn't do sex work they wouldn't be sex workers 
Should I be supporting the right of low paid workers to do low paid work too? Or should I ask for better?
Depends on what your goal is. If you make big money and then say: "#supportpoorpeople' without taking any action you're a hypocrite.
If you help them get better jobs, than you don't support low paid workers. You act in protest of low paid work.
People have forgotten what it means to support or protest because of all this slacktivism. Support is to enforce, protest is to change.
Like the other day a party here organized a 'protest' for Afghanistan. And I'm like, what are you protesting against? Sharia? Joe Biden?
"No we should open the borders for refugees"
In that case, they are supporting open borders not protesting Afghanistan

If you are supporting sex workers than you are working in favor of more sex work.