The truth is, if someone stands in front of someone, blocking their view of the game they'll more than likely be getting politely asked to sit the fuck down.
They've paid their hard-earned just the same as the rest of us, and are entitled to make use of their seat if they see fit.
Hampden isn't a standing stadium, and I'm fairly sure the stewards will be enforcing that rule once the game kicks off.
Hopefully they won't be enforcing the rule too much in the signing section though, which is where I'll be. I'd imagine that everyone will be standing there.