They use our name because we started the faction, that doesn't mean they're the same as us.
Many Capitolists have taken to wearing variants of trending garments from elsewhere and then making those garments more Thydian.
Honestly, we're not barbarians - we're civilized as much as anyone else.
Several cities in Capital are based on former cities of the Adrakian Empire, and while the lower elevations may have torn town the entire city to rebuilt, many still use Adrakian features such as an underground sewage system.
Saint Antral Overthrew the Adrakian Empire
As the Empire held its capital cities in Capital, when Saint Antral led her forces through the region, her followers vandalized the draconic iconography they found. This has led to Capital being the region with the fewest intact ruins to study or excavate.
People within Capital are more likely to complete pilgrimages to locations such as Antral's Tomb and the than non-Capitolists.
The Crowning of Magnus the Red-Eyed as High King
At the end of the Unification Wars, Arle Magnus was crowned High King for unifying Theydim under his banner. This has led to a rising sense of pride, and the Capitolist culture turning into a portrayal of a "standard" @Thydian.