How come Angelic Busters and Kaisers have wings but cant glide?

Well the story depicts them as children, and generally any young creature with wings cannot fly well or at all.

There's about twenty years between the first scene with the Nova in their tutorial, them as children, and the time Kyle and Tear gain their powers as Kaiser and Angelic Buster. The black screen that divides the time periods says something along the lines of a two decades past or something. I think it might just be the AB tutorial, I don't remember it in the Kaiser one.

Okay, it says decades later, so it's potentially 20+ years.