It’s not arrogant. Clients hire YOU to be the expert. To make the tough decisions and defend that decision with research, data, and analytics. If the client wants something that is bad design and won’t listen to you, then they might be bad clients. You should have a statement in your contract that says if the client starts making bad decisions that affect your reputation and make undue design restraints then you are liable to pay me this percentage and this is how we terminate the contract. Most medium and large size firms have clauses like that in their contracts. It should be a working relationship, not a dictatorship on either side.