If you need 10 hours to do something that somebody does in 6. Maybe, just maybe you should focus on your work instead of 'culture' especially if the goal of a start up to succeed.
I have never heard of a single case where something got acquired for it's culture. Have you?
But let me be clear. My point is that measuring somebody by the time they spend in the office only rewards people who sit in the office the most.
That's not really what their job is right? Because if that's the case I can hire few people to sit in the office for really cheap.
Me spending more time on office politics would unload some of the office politics from your shoulders and let you focus more on software development which you do the best.
That way it would be a win-win.