I think that you must just have some bad luck at upgrading. I just became a 1k for this year but for the last 4 years I have been a 1P and I have had fairly good success at upgrading many of my flights with mile. I think that I was successful probably around 2/3 of the time. And some of those were the "hard" upgrade to get like between SFO and HKG. Unfortunately I still have not figured out any pattern to when I got these and I did not.