We all need to rant occasionally, Inghinn...Yours turned into a teaching tool!
I do understand about the thread, though, and also about needles...AND putting them in correctly. Years ago, one of my sisters had put a new needle in the sewing machine and all she had was trouble and skipped stitches. Turned out she had put it in with the flat side to the front...she didn't think it made a difference...once I turned it around for her, the sewing went just fine.