The user can choose to use operating systems and applications that let him configure which apps get to run in the background and at which times. You don't want email updates while asleep? Configure your OS to implement this policy. There's no reason that hardware makers should continue to support multiple and legacy sleep modes like S3 just because OS vendors don't give users appropriate policy knobs in software.
Why is S3 "legacy"? Just because Microsoft says so?
When it is working, S3 sleep covers my needs perfectly. And it is not about email updates. I don't want my laptop to do anything while in sleep. It's that simple.
You're right. Why should hardware vendors target operating systems that exist?
Sure, S0 on Windows makes your laptop turn on in your bag for impossible-to-disable updates, causing it to overheat or the battery to run down. And no laptops on the market will S0 on Linux without running down the battery in less than 24 hours.
Why should hardware vendors mollycoddle users who make the foolish decision to use either Windows or Linux?