I agree, but I think there is more to it. By purposefully being ambiguous they throw the ball on Iran's court and "say" are you prepared to potentially have a full war against the US? That is a deterrent and at the same time they can gauge Iran's strength and resolve. By forcing them to have a "weak" response, US benefits because Iranian allies' boldness decreases.

"Israel can carry out attacks inside of Iran and they retaliate in such a weak manner... They can't protect themselves, can they even have our backs?"

I think at least there is some strategy behind it.