I've seen the comments, and yes some are low effort ridicule about wearing a diaper. But the majority are ridiculing these people for making a mockery out of wearing a diaper. That's the difference. There are going to be elements in every group that punch down, but the Trump fans are made up entirely of that element. That's why they are making a mockery of wearing a diaper in the first place.
Instead of getting defensive, try taking a step back and look at what people are actually doing rather than focusing on the few bad examples and lecturing all of us about being ableist.