14.22Why it works so well

Because each voice often moves by a semitone.

Take:

C major:

C E G

C♯°7:

C♯ E G B♭

Dm:

D F A

Notice:

C → C♯ → D

E → E → F

G → G → A

B♭ → A

Almost everything moves smoothly.

So the chord sounds like motion rather than an arbitrary interruption.