I look at it like this, some do it a little some a lot, some only when they are clearly in charge. On and on. In your case its simeple
You are PAYING this trainer to teach you, you seem happy with their level of competance, ok not ok doesnt matter. Neither is abusive or harmful, so follow the methods you are paying to learn. Its that trainers call.
I don't even give my horses feed until they learn respect, far as they know they are getting my left overs, I put feed in the bowl and stand over it with my back to them and will run them off if they get close to me. Then I calmly walk away. That is my method for quickly letting them know I am the boss in this field. Not saying its perfect or the best but it is mine and I like the results I get, think how that would work if soemone was behind me feeding thehorse treets out of hand.
So many people have probelems with horses because they treat them like a dog. A horse is not a dog. Its brain doesnt work like ours or the dogs. A mom and dad dog go kill something, bring it back for the puppies to eat. Give a dog a treat he thinks you are the coolest guy in the world and he'll do anything for you.
Give a horse food, and he thinks you are a punk and he just took your food. Until you have clear boundries not a good thing to hand treat a horse. And most likely your trainer feels the same way, but either way that's the pro you hired , should just go along with them.