Thank you for your reply.
If it is Turbotax policy to only include legally required information on tax returns, and not include any optional information by default, I applaud that. I'm not sure that is their policy, but maybe this is an indication that it is. I hope it is.
However, it is not clear that is the policy because an e-mail address is not required on the state return I am filing either and Turbotax included the e-mail address on that return by default. So it seems inconsistent. EDIT... I might be partially mistaken about this. I don't really remember how that e-mail address got there, but in any case it is there even though it is optional. So even if I entered it myself it is still inconsistent if the 1040 does not allow you to enter it.
In addition, I think the user should optionally be able to add any information on the return for which there is a field to enter it. Don't enter it by default, but don't prevent the user from entering it (There may be a way to enter this on the 1040, but I could not easily find it if there is. It seemed that field was locked.)
