So Badger, being an isolated forest gnome, know of the two different nations of humans. One is inherently bad, the others has raiders and bandits, but also farmers and people who are kind to the land. He did not know what elves, dwarfs, or goblins are. At this point, most reacts to other races are a blank slate.
Elves seem like forest spirits, so they fine. Badger is shy around humans, including those in his own party. The party discovered a massive abandoned Dwarf city that was stripped an abandoned without sign of war or death. Why who a race spend so much energy building a place and then leave without being forced to? The goblins are cowardly and crass, attacking when they have numbers.