It's fine if you don't want to eat out, but I would not consider it a "good goal" for most people.
Taken in that context, it's a good rule of thumb. Less advertised food items do tend to be healthier, because they generally require more meal prep and are just raw components.
"As you’ll see below, it’s not so hard to eat bountifully and stay under 2,000 calories. It’s just hard to do so at most restaurants."
It's fine if you want to eat out, it's just not the best way to achieve your good weight loss goals.
You can totally eat reasonable portions at restaurants. You can lose weight eating at restaurants. Yes, it's probably a bit harder, mostly because you don't fully control the portion sizes, but it's entirely possible. Many restaurants also have reduced calorie menus now.
In Defense of Food. A 3min video.
https://www.youtube.com/watch?v=37NHX2iZrBA