From my perspective..when yuh say stand up in the stadium...yuh mean by the railing in the back or when you in your seat?
Reasons in no particular order...
1) It is the best view of the pitch...uncovered is lower than covered. Thus the top row of seats and or the railing at the back gives you the best view.
2) Tradition...my old man and uncle...NEVER sit down to watch a game. They always stand up and lean up in the back. However it is a spin off of certain happenings...in 88-89 when we had qualifiers in the afternoon 3-4pm kickoff the sun was too hot when you reach 1-2 pm...so they used to chill underneath and kickoff time come upstairs and just restback...not bothering nobody..not jumbieing nobody for a seat.
3) Late comers...stadium full, game done start...yuh cyar be looking for seat and mashing man foot etc. So you stay in the back and breeze.
4) Uncovered used to be CONCERETE...it was no chairs...some parts had wood and it used to have splinter and rusty screw and ting. To keep yuh pants in order you used to sit in the aisle (concrete part) or STAND UP in the back...A tradition that is maintained today. It was also more comfortable.
5) Easy meeting area, and easy to see your partners.
6) SOme people lean over the railing to watch they partners come in.
7) The best gape is in the back...all the girls who not watching football or who hustling toilet does be walking up and down in the back like they wukking taxi.
The beer and pie men are located there so you getting yuh drinks cold (sometimes before they run out) and yuh pies warm.
9) Bandits like to hover near the top of the railing and jam people going down the step and grab chain etc.
10) Some people find the seats too hot and claustraphobic and want free breeze up top.
11) Some men like to bun they lil sess and ting and doh like to be around the crowd, hence they go in the back behind the goalpost.
12) If you in yuh seat and the man infront stand up...Only a arsehole go sitdown behind and stay not seeing nuttin...Stand up too...and get the view of the field.
13) Sometimes yuh does have to rise above the umbrella and ting in the crowd, some people refuse to close their umbrella.
14) Some girls like to stand up on chair and wine, others does be jamming girls...cyar do that sitting down.
15) When men have instruments in the crowd..they stand up to beat them as they have the iron/drums etc on small stools, tables racks etc. so them standing up..you hadda stand up too to see over them.
16) If you get a seat down below...the damn yellow fence and the advertising boards does jumbie yuh view. Stand up to see better.
17) People does stand up to makko a bess ting, some kinda arguement or fight or try to listen to Landing make one of he jokes.
18) WHEN THE GAME GOING GOOD AND IS PURE VIBES AND YUH RALLYING THE TEAM>>>YUH CYAR DO THAT SITTING DOWN. Yuh must jump up when goal score and ting.