What’s with jiffy lube and bad techs?

Our shop is a block away from a jiffy lube and about at least once a week we get a customer from there that wants us to double check work they just got done from there. Last week a lubey left a drain plug loose and the guy just drove off and came to us when he started hearing knocking. Another customer got filters done and was getting trash blowing through the vents. They offered to replace their filters and when the customer declined they didn’t bother putting them back so all the trash it caught was blowing through the vents. There was so much shit that it burnt out their blower motor and had to get it replaced. Another guy got suspension work don’t by them and as he was driving down the road the struts fell apart because the “tech” left the center nut and the three nuts that hold it on loose. Do all jiffy lubes just hire bottom of the barrel people? I mean they get us plenty of new customers so I suppose it’s not all bad but I do wonder why people keep going to these places and why they haven’t gone out of business yet