The Kaylons CANNOT possibly be this stupid
While the Kaylon desire to destroy all biologicals seems to make sense for them, it is bizarre that a group as intelligent as they are would consider this as a viable choice.
They are about to initiate a galactic war that they cannot possibly win. Even if they are successful in destroying humans on earth, there are other biological beings all over the galaxy (some with more advanced technology than earth has) that would fight back and succeed in destroying the Kaylons.
Just remember.... Earth is only ONE member of the Planetary Union, and any attack on earth would draw the other members into the fray.
In this latest episode Capt. Ed Mercer said: "We are over 300 planetary governments working together to ensure that no single world imposes its will upon another. We treat each other as equals."
The Planetary Union is a federation of space flight-capable species based at Planetary Union Central on Earth. The Union consists of science and exploratory vessels, a unified military, and a quasi-government overseeing affairs among colonies.
It is extremely difficult to wage war on two fronts.... much less on 300 fronts.
Can any race of robots that are smart enough to wage war billions of miles away also be so stupid and arrogant as to initiate a war with 300 adversary planets?