I don't either but my tires don't age out typically. I could see someone who expects their tires to age out but is not planning to use the tire to it's max cornering/stopping/weight/whatever not wanting to spend more than they need to. If I owned a beater that was used only around town I'd be tempted to go cheap too.
the stuff made by Sailun and Sentury seem to get mostly very good reviews so that would be brands like Blackhawk, Delinte and Arroyo... and then another brand called Armstrong made by another manufacturer.