Yes it can be a little annoying but just how it is, I just looked at mine and I have left 72 and received 53 I have only ever bought here and never sold. I make a point o leaving feedback for each transaction and, unless I have stuffed up, I believe I have left feedback for every transaction I have been involved in. That said, I get that not everyone's circumstances are the same and sometimes it is just a case of selling and moving on. If there is no issue then there is no further thought.
I went and checked my feedback out after reading what you wrote.
I left 144 feedback for others and received 107 feedback from others.
The figures I see under my name that I don't understand is that my feedback shows 73 left from others with 100% positive, 0 left negative feedback, but in another part it shows a total of 109 positive feedback received. I guess not all feedback shows up.
I try to leave feedback and a thank you after each transaction and it looks like I get about 75% return feedback. I guess that's not too bad.