Many possible reasons: - still part of current Windows (unsure about specific code, but 32-bit Win7 still has enough code to run Win3x apps, possible Win8 does

Many possible reasons: - still part of current Windows (unsure about specific code, but 32-bit Win7 still has enough code to run Win3x apps, possible Win8 does but haven't confirmed personally) - third-party code they don't have full rights to - trade secrets - pride - simply don't care