Well. -chan can be used for males too.
In hindsight, pretty sure that knowing that this series exists influenced me on this point. I want to watch it now.
We need a sprite hack.
-chan can be used on young children, grandparents, cute animals and close friends, and I guess anything if you really wanted. It sort of suggests you find the subject cute/endearing. If used on a male that you aren't close friends with (or even if you are maybe) it can be condescending.
I see. I'll interpret it as everyone being sarcastic and condescending toward Ika because they're dicks.