Good for this bakery! Uniiformed officers already make people uncomfortable, adding arms to the situation is could be terrifying for anyone, let alone someone who has any sort of PTSD or general fear of the police.
The police can't seem to see the situation for what it is though. It certainly isn't discrimination, LEOs are hardly a protected class and no one is saying they can't come in once they ditch the uniform and weapons. It's more like the opposite of a no shirt, no shoes policy.