Apparently, that's how crowded their real stations (not to mention the trains) would normally be during rush hours. That must explain why TOMY left so much room there. Here's an example of Shinagawa (not the infamous Shinjuku):
Now, imagine the chaos if Plakids were to have metal feet and some powered magnets would roam (or vibrate) under the platforms; They'd either knock down each other, end up where they shouldn't or simply fall over.
Over 100 passengers and staff, yet none of them can even board 95% of the trains.