Sorry to be burstin' some bubbles, but Servants don't take traits of the world they've been summoned in. They get [i]knowledge[/i] of it, like how to speak modern languages, and some knowledge of culture and science so they can blend into society and not suffer crippling culture shock.

Plus, even if Gil was summoned in the modern age, he was summoned in the 1990s in-canon and was [i]still[/i] an arrogant prat. I don't think a 10 year difference can see society change [i]that[/i] much.