As long as you're productive and meeting deadlines, I couldn't care less about the "hours" you're in the office.
Also, the market well balance itself. If someone is more productive they'll be rewarded more.
I just don't want the "equal outcome" crowd to start enforcing equal pay when most of them are clocking in minimum hours and others are over-delivering.
This is for merit based companies, which personally I can't fathom non-merit based ones.