Did you play Aion at launch? They had one starting area for each race and there were MASSIVE queues and when you did get in there were far too many people around to do any quests. It took me about 4 days to get to a level that most of my guild had got to within the first hour or two.
So by giving people with better connections the advantage you are allowing them to avoid the massive queues and be able to clear the starting areas long before everybody else. So although it may not seem like that much it could give them a 3-4 day advantage over those with poorer connections, which is quite unfair.
But then Aion did let us predownload, so I don't get your point? Yes there is always an initial rush in these games, but everyone experiences it, at the end of the day it's the people with the most time to invest who have the adv antage, not anything else.