Security of any account is most important thing, if you have an Apple id and its live then you should on the two-step verification same as in Gmail. A report from The Verge that Apple id can be hacked by your Email and Birthday.
It can easily be hacked all they have to give is your correct birthday info at this point they can easily reset your password, those who already activated their two-step verification they are save but new user’s are not they have to add two-step verification. If you don’t want to lose your id or exploits don’t use it then go and add your two-step verification for general security. Apple user’s are reporting they have to wait for 3 days to enable two step verification, in the mean time you should change your birthday date in your profile.