A few words of possible dissent.

1. If you enjoy cooking, then time spent doing it isn't a pure cost. Many people enjoy cooking. I happen to be one. You might turn out to be one too.

2. If you pay money for food, all the money is gone. If you spend time cooking, you can do other things with some of the same time -- if there is someone else around, you can talk to them; you can listen to the radio or (intermittently) read; etc. So beware of simplistic time/money tradeoff analyses.

3. Cooking is a useful social skill as well as a way of getting edible food for yourself. (You can invite people over for meals, which is by no means socially equivalent to inviting them out for meals.)

4. Good restaurant food is quite expensive. (Admittedly less so in the US, where I think you live, than in the UK, where I live.) If your tastes aren't cheap, eating out a lot may not be such a great tradeoff even if you regard your time as very valuable.

5. The time-cost of eating out is not zero. Depending on where you eat, it may be distinctly more than the time-cost of cooking for yourself. (Though, again, you can do other things while you wait for your food.)

6. I am not accusing you or Academian (or anyone in particular) of making this mistake, but: Beware of simple-minded time/money tradeoff analysis where you assume the value of your time equals (or even is well approximated by) the amount you are paid. That's a safe assumption if you actually have the option of adjusting your working hours ad lib and your behaviour is perfectly consistent, but not otherwise. (I could save myself some time by not cooking. I am paid quite well. But since I'm paid an annual salary rather than an hourly wage, I can't simply spend less time cooking and more time working and get more money at the same rate as I'm paid at.)

7. Cooking for yourself may well get you a healthier diet; you need to consider how you value your health as well as how you value your time.

I'm quite sure there are plenty of people for whom cooking isn't a good use of their time, but I suspect there are fewer such people than a simple comparison of costs with pay rates would suggest.