Yes, they will absolutely care, but they may not say anything within earshot. However, you'll never see them again. I think spandex is a privilege, not a right, and I've seen many people wearing skin-tight pants/shorts/onesies that leave little to the imagination. Just rock the bikers under some. regular shorts, think of the children... and me.
Only reason to wear them is if your legs are so fat that your inner thighs rub together and it would prevent your skin from chaffing.... Otherwise I don't see the point given it is just going to make you hotter than if you weren't wearing them.
Reminds me of my old house, a neighbor used to wear a speedo and flip flops to mow his lawn... While some guys might get away with wearing speedos outside of a pool... 60 year old fat dudes with man aren't in that group.... To me speedos and spandex has its place and usually it is reserved to the sporting arenas where it makes sense.
Mud wrestling. You could wear them for that for sure!
I dunno, I've seen plenty of women and children wearing bike shorts in the Orlando theme parks, but they tend to be the slightly loose-fitting ones. I've also seen plenty of women/girls wearing other workout clothing, including onesies (the kind that are a top+shorts all in one) and tennis dresses.