It is somewhat of a diverse topic. I suppose that some women would say that the reason behind why men wear panties is the indicative factor in why it may or may not bother them. Well, they do for many reasons. Some men have told me that it is because women's panties are more comfortable and the material is far better than what is offered to men in traditional briefs and boxers. Some men wear them because they enjoy exploring their feminine side and it makes them feel sexy.
Some men are trans-gendered and it's part of their new identities.
Some men wear them for stress relief. My feeling is that it's a piece of material, and no matter who or what the original manufacturer had in mind, it doesn't matter. It's such a small thing in the scope of that big world out there.