People do what they feel comfortable with. If they feel they are making progress, it is their business.

Wow, why all the whining? For a beginner, those questions are fine. Expecting someone to start out at C2? There are many reasons someone might keep it simple; it's not like they have planned to spoil your conversation. If you don't like it, switch partners. 

Who you can find on italki:

1 the "flirt-user" (useless but funny);

2 the "obsessive-user" (run, they will destroy your life calling you on skype 100 times per day);
3 the "premium-user" (they are too rich and snob, don't talk with them);

4 the "Hi-user" (I love them; they're 70% of italky community).

They register on italki because they are only able to respond in short answers.  If they were fluent, they wouldn't need this site.  The fact that they use short answers is indicative of their level of fluency & their fear of appearing ignorant.  My answers today are far different than my answers from a year ago and my answers a year from now will hopefully be more complex as well.  You should also factor in cultural differences & inherent shyness.

I don't think using those questions/answer is a bad idea. Those question are ok to meet new people. I'm sure you don't want people ask about your religion or another personal question without even greet or present themself.