Tao te Ching: 24

He who stands on tiptoe is not steady.
He who strides forward does not go.
He who shows himself is not luminous.
He who justifies himself is not prominent.
He who boasts of himself is not given credit.
He who brags does not endure for long.
From the point of view of Tao, these are like remnants of
food and tumors of action,
Which all creatures detest.
Therefore those who possess Tao turn away from them.

Reaching, making a concerted effort, and showing off are all signs that one isn't doing the thing they should be doing, but instead are making a show for others benefit. "Look at me, I am fantastic because..." and because the effort is put into appearances instead of actualities, the actuality falls short.

These things are the symptoms of the effort being put into appearances, and Lao Tzu says from the view of Tao, of which a Taoist would be practicing wu-wei, these things are excrement and left over parts. They can be offensive, and those who follow the Tao stay away because they know what it signifies.