The main reason it's almost all scalies is 'cause... that's what we as devs like the most! That and anthro furry games tend to usually focus on big fuzzy wolves and whatnot, so... something different for a change!
There's probably other races out there, though! You might even meet them in the future, potentially. For now though I'm glad you enjoy all the lore and world-building! Hope you'll continue to look into things, examine things, and stick around for future updates!