I agree that the Tudeh was worrisome, but in hindsight a far better result would have been obtained if the US had not supported the British policies that drove Mossadegh toward Tudeh in the first place.
People say hindsight is 20/20, but that’s only half true. We can see the results of the path taken, but the path not taken isn’t necessarily any clearer. For example, we know the problems caused by removing Saddam, but we’ll never know what would have happened if we didn’t, which might have been worse. Same with Mossadegh.
BTW, Mossadegh’s coalition also included the Iranian Islamists of the day. Now they are allied with Russia again. Strange bedfellows as they say.
Sort of like we should have supported Ho over the French in 1945, instead of handing them their colony back.