I think that's their rule and you can choose not to go. Our June trip was already canceled. We are not going in the heat while wearing masks. I'm waiting for cooler weather if masks are required.
It's like anywhere else. Menards and Costco here require you to wear a mask. You don't have to go there either. You can choose to shop elsewhere, but if you want to go to Menards you wear the mask. You want to go to Disney, you wear the mask. People can stomp around angry all they want, but if it's that much of a frustration, just don't go. I feel bad for the cast members who are going to have to deal with adults having temper tantrums because they don't want to follow the rules.
You summed it up exactly with the “temper tantrums”. Adults getting so worked up about a private company telling them to wear masks, that’s exactly what it is. A temper tantrum.
You don’t like it. Don’t go. Simple.