If you complete phone screens on 1 out of every 10 inquiries you send, you are doing very well in my opinion.
If those phone screens do not turn into full interviews or offers, that is a statement on how they went, not on company responsiveness.
Frankly, I don't think your stats show a lack of response at all. I think they are very reasonable, as some level of non-responsiveness is natural, when you account for the fact that you gave them enough information to summarily dismiss you from consideration if you don't match their needs or culture.
But even a summarily dismissive response is better than silence (click 'reply', paste in "Sorry, your cover letter doesn't indicate a good fit", click 'send').
While I agree with the author that there does seem to be people just wasting time in the market, I did have the same reaction as you to the phone screen numbers. 8 out of 10 of my phone screens convert into an offer. There is a very human element at the point of a phone screen and maybe that has something to do with the numbers. If the author was just doing an experiment and not truly interested in the position, it may have show through in the phone screen or there could have been other issues with it. It seems weird to me to get to the phone interview and just waste time.
If those phone screens do not turn into full interviews or offers, that is a statement on how they went, not on company responsiveness.
Frankly, I don't think your stats show a lack of response at all. I think they are very reasonable, as some level of non-responsiveness is natural, when you account for the fact that you gave them enough information to summarily dismiss you from consideration if you don't match their needs or culture.