Makers of PC computer systems that are made by sweatshop workers in third world countries in textile mills. They use unreliable components and often take cost-saving measures such as: building everything but the kitchen sink onto the motherboard so it is unlikely anybody will ever try to upgrade. Software only modems. Bios that does not recognize a boot drive unless it is pre-loaded with mindless Compaq shovelware. IDE ribbon cables with only 1 head. Riser cards for horizontally oriented PCI slots.
Best of all they pass the saving on to you, the consumer. Oops, sorry, that last bit is what the other computer manufacturers do.
My Grandma upgraded to a Compaq from a 286 PC Jr. and noticed a slight decrease in performance. Also the XGA graphics on the old computer were better.