I'm afraid it is because you are so young and most users of italki are grown ups. Adult language learners will want to discuss subjects that may not be suitable for children, or issues that you maybe do not have enough knowledge/experience with yet.

Also more importantly, in Western cultures it is not acceptable for adults to communicate with children they do not know on-line, unless it is a professional capacity. We would be looked upon with great suspicion if we were found to be communicating privately with children we do not know. 

You can still however try writing notebooks on here in English, people will be willing to correct your work and have contact with you this way. Also maybe your parents could pay for you to take lessons with one of the teachers or tutors on the site. 

You can also try starting discussion threads in the discussion section, and talking to people about different topics there. You will hopefully find if you write notebooks and start discussion threads, you will get to communicate with people more.

The key is you must be prepared to communicate with us openly in public on the main site. If you want people to write to you privaetly and chat to you on Skype, QQ etc, you will find them unwilling to do so.

I hope this helps! Why not go and start your 1st discussion thread or write an English notebook, now!?!