Why won't my GUI work when I access it from ServerScriptService?

function Start()
	for i = 10, 0, -1 do
		game.StarterGui.Intermission.TextLabel.Text = "Game beginning in "..i
		wait(1)
	end
end


while true do
	if game.Players.NumPlayers >= 3 then
		wait(1)
		Start()
	end
	wait()
end

StarterGui contains GUI object, but it is not what the player is seeing. A player sees everything inside PlayerGui. Each time a player's character respawns, everything in StarterGui is cloned into PlayerGui. In studio, we can see things in StarterGui for editing purposes, but the player only sees what is currently in his PlayerGui.

To get this to work, use a for loop to loop through each player's PlayerGui and edit it.

for index,player in pairs(game.Players:GetPlayers()) do
	player:WaitForChild("PlayerGui").Intermission.TextLabel.Text = "hola senor!"
end