Glican's are most known for keeping with their traditions. This and their healthy fear of the Gods retribution keeps them from advancing any farther than they have.
Full breed Vs Half breed
The purist notions have always been that a full breed is better than a half or mixed. Their belief was that reproducing outside their race was a sin and a crime. Eventually during the Purging Era enough people gathered to start a strong force to carry out the slaughtering of millions of people.
The mixed breed people weren't the only victims, the Purists went after those who hid them or was rumored to be hiding them. Because it was so easy to blame someone many innocent people had been killed due to a jealous neighbor or vengeful family member.
After it all settled down people were still afraid of being seen with mixed breeds and started a hatred against them. The only places left that willingly let them in are the Free Thinking Towns.
Free Thinking Towns
During the Great Purging Era these towns were refuge for half breeds that were being hunted down. There are very few left after things calmed down since many were burned to the ground. Free thinking towns continue to accept those of mixed breed or any other strange creature that comes their way. New technological advances and other taboo things are accepted here too, and might've advanced much like the Cursed City if they weren't afraid of persecution from neighboring towns.
Slavery
Slavery was started by the Valent race, when they were in desperate need of people to copulate to sate their lusts. It thrives strongly even though there are many towns and cities that have banned it from entering. Many of the poor souls are made into sex slaves if they are pretty enough, or turned into workers. People in slavery do not live very long unless they are a favored companion. Each of the slave traders has a particular wing trademark they place on their wares. This symbol is a mockery to their captives, who cannot be 'free as a bird'.