Typically being 3 or 4 major versions behind the current version is under %0.5 of the market, it's really not worth it to maintain compatibility that low unless

Typically being 3 or 4 major versions behind the current version is under %0.5 of the market, it's really not worth it to maintain compatibility that low unless your already old app doesn't need to stop supporting old versions. I'm estimating because the app is newer, is the reason why they didnt' put special effort in support very old versions like that.