I believe in team building over lunch, but free food is a terrible attractant and retention item.
People who are intrinsically motivated to do excellent work might be motivated to join due to food, but they really join for autonomy, mastery and purpose. Free food is none of these things. And ultimately you end up attracting people who are after the perks, and may not end up contributing to a passionate environment.
Free food helps people focus, as the post says, when you're not figuring out what to eat, mooching out the building then being a bit annoyed that there's a queue and then you're forking over cash, you're not focused or thinking about problems.
You gain purpose when you're sat around a table bonding with teammates and bouncing ideas. The lunchtimes I had as an intern at Google were incredibly valuable to me. They were hours which I didn't consider downtime at all.
People who are intrinsically motivated to do excellent work might be motivated to join due to food, but they really join for autonomy, mastery and purpose. Free food is none of these things. And ultimately you end up attracting people who are after the perks, and may not end up contributing to a passionate environment.