The "they wouldn't do that with other groups" is beaten

I agree that some people go to that well too often. I try not to use that comparison for the most part because there's absolutely no way we're going to past the "short people were never slaves and were never denied the right to vote" nonsensical talking point. However, HeightismAOS came-up with the perfect comeback for that reply, which was

"Oh, so you're saying that if black people were never slaves and were never denied the right to vote, racism would be ok."

This comeback is a perfect way to counteract their talking point, so we do force them to take-on a new idea if we use this comeback. I personally like to keep the talk about other marginalized groups in my back pocket until I present them with other info, such as how tall men are praised for the same behavior short men are slandered for, info from statistics and studies, etc. The one group I feel like we shouldn't let-up on making comparisons to is women, but I generally don't compare us to women as a historical social justice group, I compare the
double-standards modern women employ against us while advocating for their own dignity.

As far as if it is obvious, I think it is to people who address heightism and to heightism-deniers. As a matter of fact, heightism-deniers rely on us bringing-up other groups so they can shut us down with the "you've never been slaves" talking point, so I try not to lob them that softball in most cases. On the other hand, it isn't obvious to people who have never thought about heightism. When hearing about heightism for the first time, I still hear a lot of people say something to the effect of

"Wow. I never thought about how it's ok to treat short people worse than other people from other groups."

So, basically, my opinion is that you are right that some folks overuse that talking point, but we don't need to throw that tactic away completely. The bottom line is that whether the tactic is overused or not, it's still the truth, and we are in the truth business. No matter how often our truth gets denied and how tired we get of repeating the same stuff over-and-over, we have to keep spreading the word because the greater part of society still hasn't ever been told the truth about heightism. One of our goals is to speak the truth repeatedly so that IF society ever takes heightism seriously, people will look back on these conversations and say

"GOOD GOD MAN! Those anti-heightism folks told the facts repeatedly, and no matter how many ways they presented the info, or, how many different facets of heightism they discussed, they got dismissed, mocked, and ridiculed with the same nonsensical comebacks."

The struggles we have gone through in having our voices heard needs to be part of the story if heightism is ever going to be seriously addressed, so unfortunately, part of our burden is going to be sharing the same truths over-and-over again. I definitely agree that we need to diversify our dialogue and not go to the same well every time though. Fresh ideas need to be a constant theme, and we can't solely rely on our classic talking points.