Why would someone be talked out of clay barring.
For cars that are driven somewhat on a regular basis you'll start to feel this light "grit", that's what the clay bar removes, period. Why would you want to apply wax/polish/sealant over that surface.
It amazes me that a legit "shop" would do that to you. What did they exactly do for the $100.00, inquiring minds would like to know!