Doesn't know what quality control means.
What went wrong? What hasn't gone wrong. They don't know what quality control is anymore. Crappy extruder, outdated/bad firmware, bed has 98% chance to come warped on their printer, my ender 3 pro came with fire safety DISABLED, they shipped with fake power connectors where they brown up from heat and catch fire eventually, and they don't ever test their products. They just throw the made product in it's box and ship it off. Last purchase which i returned after 3 months was their enclosure. Literally just thin aluminium foil that teared up by looking at it.