I've had good luck with Walmart tires myself, but their customer service isn't as good as Discount Tire.. I don't buy from them vs discount unless there is a significant cost savings.
It wasn't one bad tire it was four bad tires which is a little odd. Every summer they'd end up with a blowout on their trip up. Since they went to discount tire no more issues. I'm not saying every Walmart is bad, maybe it was that location or a bad batch who knows. Sure all restaurants have a bad night now and again but not consistently.
Still....it's not Walmart's fault the manufacturer makes a bad tire. Of course you have no idea of the care that the tires received and if the inflation were checked. Having resided in "The West" all my life-I can tell you a weak tire will blow in Arizona in those outlandish hot temperatures-at high speed in the summer time.