At one company where I worked, the advertised benefit to employees was, "You get to choose what you build for the company! You can INNOVATE!" Not these words, but this was the message. If you want to take initiative to improve things around here, you have to do so on your own time.

Interestingly, I ended-up spending much of the hackathon day an evening fixing a production problem which was of obvious urgency. Some mild shaming from management ensued when I had nothing to present -- a clear message.