How is that bad?
When you go to a car dealer, you know he has an incentive to sell to you.
Is it bad? No, it just is.
It doesn't mean you stop listening to him. You just filter the information to get what you need to make up your own decision.
If you distrust the dealer you can go to another dealer but you can also still work with him and maybe bring your own expert, which is popular practice.
In the end you need to buy a car and you can pretty much assume ALL dealers have the same incentive to sell to you.