I don't mean to defend EA, but maybe the 30 sec refresh was ordered a long time ago and only just now got incorporated.
I can imagine one reason for doing this. After seeing countless panels offering nothing I need, I've sometimes been given a panel containing TWO cities I'd like to visit, but I could only choose one, and the next panel would contain completely different offerings. So by keeping the panel consistent for 30 seconds, I can now visit one city, be depressed that my choice is forbidden, and visit the second city and again be depressed that my choice is forbidden to me there as well.
I get to be annoyed twice by the same panel of offerings. It's a lose-lose scenario that EA accountants must be proud of. I hope they choke on their lunchtime martinis. Only drunken accountants could insist this frustration is a game.