Where there is too much ego, there is bad design.
Onur Cobanli explains:
Designers usually don’t see what is wrong with their own designs but very easily see what is wrong with other’s designs. Every good designer is highly advised to ask external feedback, it always helps to know what you could do better. Even bad designers can spot bad design as long as it is not their own bad design. Designers should be able to overcome their ego and keep an ear open for constructive feedback.