I do not understand what point are you making.
Are you comparing Iran to Hitler?! That does not make sense whatsoever.
If you mean 'At some point, you have to step in and make the change by force. Like we did with Hitler'.
I will say: Yes, at some point it is justified to step in. But, there must be a realistic chance that you will make things better, and low chance that you will make things much, much worse. International consensus would be highly desirable, as well.
In case of Iran: How sure are you that you can make a positive change in Iran by bombing only? If you kill (directly or indirectly, e.g. starvation/ruined water supplies) much more Iranians than Iranians killed themselves (like we did with Saddam), are you really helping?
I don't think there is a will (and maybe not even a capability) for boots on the ground. So, you are just hoping that the new regime would be a better one. Not many positive historical examples there.
Last, but not least: There are serious escalation dangers. What if China/Russia provided Iran with targeting data and/or missiles (not that Iran does not have their own) and Iran hit/sunk a carrier and some destroyers? Are you now in war with China/Russia? At what moment do you cross that line? Will you retreat with the tail between you legs, like from Afghanistan? Or will Israel decide to toss a nuke or two?
The idealism of helping the poor protesters is a noble one, but the road to hell is paved by good intentions.