Do not totally agree.
Typically this is an opening question. If this was asked at the tail end of the interview, it could be used as an opportunity to sell oneself.
I personally use this question to gauge the communication skills, confidence and self respect in the candidate. I pretend to read the resume while the candidate is talking while noticing how he sits, talks, uses his hands and all the other little things. All these things added together tell me a lot about the candidate which is not there in the resume.
I haven't seen anyone asking "Tell me about yourself at the tail of interview". Normally this question is asked as a first question of interview and purpose is to make candidate relax if he/she is feeling nervous.
I agree with Arulk here.
For the people who attend interview regularly, it is practice. For people who attend interview only when needed ( not for practice ), it is possible candidate can become nervous. his/her skills should not be judged with his nervousness.