Exactly. You have control over what happens in your HOA. If you were so unhappy as to HOA policy I'm sure you could run yourself, right?
My point was that I doubt someone could move into a flag-friendly neighborhood only to have it switched to a flag-unfriendly neighborhood and have no recourse. I'm sure if you really wanted, you could even become a board member and change the charter so that all policy changes must be held to a public vote, if they're not already.
At the end of the day, you're not forced to live in an HOA. Just like if you don't like all the extra government of being in a big city you should move to the country. It sounds to me like a lot of people like the financial security an HOA brings to their property, so long as it doesn't ever interfere on what they want to do to their property.
Should you be allowed to fly a flag at your home? Absolutely. I have no problem with the resolution or whatever the thing was. But everyone gets all uppity about HOA's telling people what they can and can't do to their property when that's the very reason they exist. To keep you from negatively affecting other's property values, and to keep them from doing the same to yours. People, like always, just want it both ways.
If you wanted your HOA to just be responsible for maintaining common areas and have no say over someone's private property, then you should run for board yourself and work on implementing that change!