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.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.