They should, I agree. Not just for curlies but because sulphates are proven to thin and dehydrate the skin and are not recommended for people with eczema. People on hair forums know more than some professionals!!
I found the same as you, some/ many hairdressers don't have a clue what sulphates or silicones are. I go to the salon with clean very wet hair and get a wet cut or just trim my own hair now.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
CO-wash: Inecto coconut
Treatments: Komaza Matani, coconut oil, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume, Inecto argan
Styler: Umberto Giannini jelly, Boots Essentials gel
Experimenting with: going back to basics