I totally understand you, because I also ran into this problem before. I couldn't figure out why people just didn't reply to my requests. Then by pulling myself in others' shoes, I guess I know the reasons. If it were me who receive those requests, I would also be hesitated to accept them. For me,  I accept those who declare their intentions Just to be language partners. If the request is long and detailed, that will be better. Anyway, my tip is when you send your request, try to make it detailed ( like why do you want to learn this language or how long have you learned this ,etc) and clear on your purpose instead of just saying" Hi! I am xxx, and I wanna be your language partner on italki."  Maybe I am being picky, but that's what I've learned from my experience on italki; moreover, it really works.  I hope it can help you! Btw, if you want to learn Chinese, I am very happy to help! 

The same thing is happening to me and in my personal situation I am very aware that my English level is quite low but we're here to learn.

 It's not like a problem to me because um, the truth is I have never received requests~ and I only send request after someone has helped me or had a conversation with me. I think self-study is cool too in that you don't have to worry about the balance between your partner and you. It might just be a tedious process. My advice is to just make use of the answer and discussion board on this website.

So as usual: the few ruining things for all.  Perfect.