They are absolutely BS because 99% of programming is unquantifiable. There are too many variables. I added 5 features this quarter and sales went up 5%. Is it because of the features, or better sales techniques, or dumb luck?
"Redesigned the web pages and user satisfaction went up 10%" - but also you hired 5 more customer support agents and a backend engineer improved the slow pages by 30%.
"Created a new CMS in python (Based on the old CMS) (With a team of 2 others and one guru who did the design but I wrote his code) resulting in 70% reduction in update times (after we ran it in a cluster with twice the resources but I never could understand clustering so guess it was my coding)" "And didn't have time to write tests, and that project was canned because it took too long actually"
"Redesigned the web pages and user satisfaction went up 10%" - but also you hired 5 more customer support agents and a backend engineer improved the slow pages by 30%.