you are totally correct, I've never been treated as bad as in the Dubai terminal, even in neat uniform and a 2000 US dollar (actually payed for) ticket in my hand.
It's like the uniform gave me a "treat this guy as ****" stamp on my head. I don't expect a royal treatment but I expect the normal stuff you know.
For spain, you actually get the royal treatment, cabin crew stops you when you enter the aircraft, they will arrange the best seats they can offer you, they don't even look at your boarding card whether your in economy or business. And if there is no rush, the captain will even come and say hi to you.