This is absolutely terrible advice. Lunch is the ideal opportunity to expand your social network, make connections, learn from others, etc. It is by definition a small-ish block of time and if you're not feeling particularly talkative you can just concentrate on your food. Getting to know colleagues from different parts of the business will greatly expand future career opportunities. Lunch is the best way to do this,…
Simply put, the author doesn't seem to put much value in other people. That's not something I can get behind.