There is no true scotsman. Doesn't mean we can't have truth
The fact is that we don't have neutral institutions. Even theoretically it would be extremely unlikely, and in practice it won't happen, chiefly because it would involve people in the in-group making comittiments to deplorable people in the out-group.
This might be approximately possible in a united cohesive high-trust society... but that bond of kinship simply doesn't exist anywhere in the West today
Anyone can strive to objectivity. Even if you can never reach it, the quality between someone who tries and someone who gives up is tremendous.