Who cares? If you want to wear a mask, it's none of my business. I think you're overthinking this.
Let's face it, we've seen people at WDW wearing masks LONG before this pandemic hit, and due to them already have an issue with their lungs or weak immune systems. We never gave it a second thought.
The only time I DO question mask wearing is when I see people driving down the street alone wearing masks. Why? Are they afraid they're going to infect themselves with cooties? There's nobody WITH them!
Otherwise, you do your thing. It's nobody else's business why, and believe me, 99% of the people could care less WHAT you're doing, ESPECIALLY at a park. The remaining 1% are going to look at you sideways anyway, REGARDLESS of what you're doing.
Regards! Michaelson