While I understand the position of COSTCO, fully designed by lawyers and not much else, I get really irritated that they don't allow the customer make their own decisions. Enough that I don't buy tires there although I did buy 4 new tires for older son once.
I have driven motorcycles, some heavy trucks (drove a dump truck working construction in college),FWD, RWD, 2WD, 4WD and AWD cars with open diffs, limited slips, locking diffs, ABS and ESP (electronic stability system). A couple years ago I went 1K miles off road in my Jeep. I know that 4WD means you can go and not that you can stop. I have 'severely' under and over inflated tires to get traction in specific circumstances. I understand the limited area of concern that COSTCO has. In FWD the front wheels drive, turn and do most of the stopping; the primary purpose of the rear tires is to just keep the car straight, not contributing much to stopping effort. (Anybody remember empty pickup trucks before ABS and no load, don't care which tires had the most thread there was a good chance of the rear end getting ahead of the front end.) Now ABS has solved a lot of the concern COSTCO should have and I even have ESP on my Jeep. Now the COSTCO position has a small validity about stopping in some limited circumstances, especially where someone doesn't know what they are doing, including going too fast. But they provide no help to the fellow stuck in snow in his driveway or in some mud where good thread on the drive wheels is what is needed to get going. So they are worried about whether you can stop but not whether you can go.
I buy my tires from a speciality supply tailored to my needs, like extra layers of sidewall for off roading or towing, performance tires for DWs Miata and really strange tires for the 1985 VW camper. I simply will not buy @COSTCO. If they had a tire I want at a good price I expect my tire guy to match it as he already does for Tire Rack tires. If somehow I ended up with COSTCO tires I would rotate them myself as I see fit. While I really like COSTCO for most things I don't even bother to visit their tire dept. Folks there just read the book, have no knowledge or judgement and don't allow their customers to have any either.