Are there reasons for not storing boolean values in SQL as bit data types?

Question

Are there reasons for not storing boolean values in SQL as bit data types without NULL? I see them often stored as integers without constraints to limit values to 0 and 1,

Answer 1

I use bit a lot. But sometimes I want to be able to have the ability to return false - or many values of true (like error messaging). So if I use an int instead of boolean I can doe something like:

0 = False 1 = Password incorrect 2 = Username does not exist. 3 = Account locked out - to many failed attempts. 4 = Account disabled.

And so on.