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

one reason is that people don't know about bit or think that y/n is simpler for formatting. other reason is that sometimes you think: hmm maybe over time this will be more than a bool field. and you make it int just in case.

you're not missing anything :)