Well first of all, I am never in this situation. I refuse to go to WDW in the summer. If given a choice between going in the summer and not going, I pick not going and I am a die hard Disney freak.
Now, yes to some of us it does matter how we look. Shocking I know, but when I don't feel good about how I look then I am in a very bad mood. For me personally, I find tennis shoes to be very uncomfortable and very hot, I mush prefer flip flops, My feet aren't damaged, been doing this for years, and I am perfectly comfortable in them. I realize others aren't but for me, tennis shoes are for working out and only working out.