Makes me want to fly a Hezbollah flag myself.
I get your feeling of injustice, putting them into relation. But flying a Hezbollah flag doesn't change that, and doesn't support your argument. It just supports Hezbollah. You can criticize without supporting the next best worst opposition.
If you want to demonstrate the maximum amount of opposition, with disregard for anything else, it does that. And that may have some effect and value too.
But what's your goal, and who do you want to reach? Who will you push away by flying a flag of a terrorist organisation (looking at what they did, irrelevant why they came to be and act the way they do for now)? Isn't supporting Palestine and Palestinians, demonstrating for their right to exist and live, and against Israel's terror - isn't that just as viable? Isn't that the goal? I don't think there's a need to support Hezbollah or fly their flag for that?
Israel should definitely be held to the same standards, which it currently is not.