I disagree, I don't think it's inconsistant at all. The Andalites as a general population did not think that the Yeerks should leave their homeworld. They even had a military base on the Yeerk homeworld (overrun at the beginning of HBC), presumably in case something did go wrong with their diplomatic procedures. It could be inferred that the Andalites (who we know to be a bit self-righteous and a smidge arrogant) were ready to use their military force to control the Yeerks should diplomacy fail them.
Seerow, who is an Andalite but does not represent all of Andalites as a specie, pitied the Yeerks because they spent so much of their lives blind, deaf and helpless. He wanted to help them explore the galaxy, and so he facilitated it.
The Andalites as a whole did not build portable Kandrona for the Yeerks, Seerow did. As Aftran put it, in the eyes of the Yeerks he was the one good Andalite.