The system is designed that way. Will power is a finite resource, and people get pummeled so hard at work, their need to execute what tiny bit of freedom they can scrape off the world results in their eating a tasty but unhealthy lunch at a chain restaurant to "treat themselves". Our whole society wouldn't function if people weren't exhausted to the point where their brains malfunction and they make bad choices.

Wait till they bring Jira and Agile to your tech job, though. You'll find yourself "needing" expensive toys again.