The free perks are great, but are not the core reason that make Google's work environment compelling for the many that love it (and they don't offer unlimited time off, although I know you don't mean that literally).
Google offers a very healthy working environment for many people. It's a large and diverse company. Not everyone loves it here, of course. But many do, and it's clear it's offering an environment that has real value and pull, and tries hard to respect and empower those of us down in the trenches.