Not really. Its like everyone loves shakespear just cause its shakespear. Someone will read his plays, and no matter what they will herald it as a great play because its shakespear. They dont really look into it. Just because its a spit is not a reason for it to be the greatest aircraft of all time. I want to see EVERYONE who voted for the spit tell me why its so great, and no, just cause it looks good is not a reason for it to be the greatest aircraft of all time.
Well, I actually voted for the DC-3 myself, lovely and relaible 'craft.

However, had the Spit been in another poll, I could have voted for both

But I can give you my reasons why I belive the Spit is so great.
Coming from Britain myself, we are obviously (almost) all Spit lovers, but indeed this isn't what you're after.
The Spit, in the BoB and throughout the war, helped a great deal to save the British. The Hurricane played it's role in the BoB, but the Spitfire developed greatly throughout the war. Different engines, versions, tweaks, the Spitfire developed hugely all for the role of dogfighting, keeping the threat of (what could have been) our survivial, my grandparents' survival, many people's parents/grandparents survival.
It also filled the aspect of beauty - you want to know other reasons for voting for it, but a beautiful aircraft is always a popular aircraft. Like the DC-3, it looked glamorous and welcoming to airliners and passengers alike. The Spit was a sleek fighter, loved by people during and after the war, and has gone down in aviation history because of reliability as a fighter, looks, everything relevant to a WWII fighter.

I do say that choosing the "Greatest aircraft of all time" is indeed a very difficult, almost bordering on impossible task, as aircraft are used for so many different things, then and now, and they each succeed in different roles.....hard to choose isn't it? ;)