Can a recipe that yields 30 cupcakes Be converted into a 2 layer cake?

A standard box cake mix will make about 24 cupcakes; you should be able to make a 9 or 10 in round two-layer cake. Rarely, a cupcake recipe will be too tender (or fragile) to hold up well as a layer cake, but only you know how delicate the cupcakes come out.

I'm assuming it would turn out fine. I have used cake recipes for cupcakes. But I am wondering why you don't use a cake recipe to be safe.