There is a difference between what the chef will do for you after a one-on-one discussion vs. what their marketing people will claim in written documentation that will come back to bite them in court if you get sick and sue them. We live in a litigious society, and it impacts our communications.
But they are right -- if you are Celiac, and it is so serious that a shared utensil is dangerous to you... their CYA statements are probably correct that it is not advisable to eat there. That doesn't mean you cannot do it... but it is your decision whether to go against that advice, and take that risk upon yourself... not their decision to give you a green light and put that risk on their kitchen staff.
For me, having to have a one on one discussion with the chef (not my comfort zone) about whether they can make celiac-safe food isn't the same thing as almost every restaurant having gluten-free items on the menu. BTW, plenty of restaurants seem to list fried foods that are gluten-free but also mention that they share the fryer with items containing gluten. That's not legalese, that's certain contamination.
I said it above but i want to say it again - in a well run kitchen, there should be no shared utensils. Even common kitchen tongs should not be shared between pan's, and should be cleaned between each meal.
In my opinion (not so humble haha), if you can't even do that, you don't belong in a proper restaurant.
Sadly, a lot of hacks exist in the world of food. It's refreshing that you're far from being one of them, and definitely it pays to eat at a restaurant that has pride in what it does. I think more broadly, you just have to choose wisely! I'd rather eat your food once a month, than a chain's once a week.
The ones who weren't trained at least, you can help. The ones who have no pride in what they do, the hacks, should (as you said) not be in the world of food. There are a lot of people like you though, and one good thing that popular culture has done is to recognize that good food takes time and care. There might be a lot of people preparing and eating crap, but there's more good, respectable food than ever.
But they are right -- if you are Celiac, and it is so serious that a shared utensil is dangerous to you... their CYA statements are probably correct that it is not advisable to eat there. That doesn't mean you cannot do it... but it is your decision whether to go against that advice, and take that risk upon yourself... not their decision to give you a green light and put that risk on their kitchen staff.