However if you have not enabled it and still get email verification code then it can't be stopped, it won't be sent everytime. It's sent if Adobe senses the login pattern does not match your normal routine, it is sort of an automatic account security.
It's not a nuisance, it's a very required security feature and highly recommended to be used. All sorts of hacking and phishing attacks take place left, right, and center, 2FA is a useful tool to safeguard against such attacks. I don't mind adding a few keystrokes while logging into an application if that increases my chances of being safe.
So please choose your words wisely and learn/study things on what they are and why they are implemented before jumping to conclusions, also if you answer is it's my choice and I don't care then I will reply many of us do, so go ahead and switch it off but don't call it a nuisance.