Why is this supposed to be an insult?

Yup

The FHA doesn’t protect speech. You seem to misunderstand how the system of the laws and the constitution work in relation to businesses and government.

The FHA does not prohibit discrimination on the basis of political beliefs. It’s not even clear you could prove that is what they are doing here, but you seem to be accusing them of that.

What about criminal charges? That hit was a clear case of assault and battery. In an incident where serious injury could result criminal charges should at least be considered.