I can only speak for myself although I suspect that was I'm about to say holds true for others - and here Im thinking specifically of my two colleagues in the high heel challenge, @mlroseplant and @higherheels, but others on here as well. For me it is a matter of aesthetics, style and elegance. I like the look of them and always have, and for years resented the fact that as a man I was not supposedly allowed to wear them too. Heels are about self expression and personal theatre and bring with them a sense of fun, and a kind of sassy delight in their impracticality.
Sure, the fact that walking gracefully in heels is an acquired skill adds something to the mix - there's a quiet pleasure to be had in doing a challenging thing well and with offhand grace, probably not too different to the satisfaction a motorist might feel in driving a sportscar well.
And yes, there is a sense of pleasurable rebellion in wearing heels as a guy - and from what @higherheels has said, wearing them as a woman as well - but if by some magic all that were to go away, I would still wear heels, as I suspet others on here would too. My enjoyment is not dependent on flouting convention, but really, very much, a love of the look and style ad the sheer fun of wearing them