The Alter Rebbe condems those, who during Davening, engage in idle chatter.
Talking during Davening shows that we have no desire to behold the G-dliness that is revealed specifically during that time.
This insensitivity is described with a moshel from the Zohar.
How for years a king hides his majestic splendor behind locked doors; those of his subjects who have the saichel to value that splendor, eagerly wait for years on end until they are granted a glimpse of it; others are so narish and kinda chutzpadik that they show no interest.
The time of Davening is a precious time 'down here', echoing a favourable, auspicious time Above.
Above, the Alter Rebbe says, is a time of Mochin D'Gadlus, a time of sublime illumination in the upper worlds.
In order to receive the revelation which becomes possible at the time of Davening , that time needs to be used for meditation on the greatness of Hashem. But for this to work, the Davener still needs to make a window in his heart, so that the revelation that illuminates his mind during davening will radiate its warmth into his heart.
It is also a dishonor to the King, when we show Him that we do not care to delight ourselves in His glory and beauty , we care more to busy ourselves with our own needs, i.e. shmoozing (or thinking about other stuff).
So now when I Daven I try to think of the Aibershters vast treasures and how I need to stand before Him in awe, and concentrate on the Tefillos. And what chutzpa it would be for me to let the King of kings wait for me while I wander off......
Thankyou Sholom B. Wineberg