Lea: The Unity design process (and how you can play a part in it)

Exactly

When learning to ride a bicycle, having training wheels really helps.

However if you then conclude that training wheels are so useful that they should be formed into the frame of the bike instead of as a bolt-on option (after all, adults can get hacksaws and other tools to cut the frame if they _really_ think they are expert enough to not need them), it ends up crippling the long-term use of the bike.