This question is just like asking which is better out of, I don't know, Apples or DVD-RW drives.
Two distinctly different sets of people with distinctly different goals. My aim is to play some classics, which I can do with WinUAE. However I can understand the feeling the playing on the original hardware gives you. Even though I emulate (and prefer it), I do occasionally hanker after the real thing.
Why? Just because.
That is the answer to why you prefer emulation or 'real hardware' too.