The high protein numbers are intended to support muscle protein synthesis. (I could drop to 30% protein according to most studies, though.) The high carb numbers are intended to support muscle glycogen replenishment and still leave me with enough mental energy to actually write code for a living. The low fat numbers are simply because something has to give.
It seems to work. It certainly works much better than my previous macronutrient breakdown, which had less protein and less carbs, and which left my lifts stalled and left me feeling like roadkill.
Anyway, eating a large quantity of lean protein is boring and time consuming. It's easy to blow 2000+ calories on fast food meal, but if you eat 800 calories of lean protein a day, it requires planning and work.
Leftovers for lunch can be cheap, healthy, delicious and basically no-prep. For a low-carb option I like sauteed Brussel sprouts, green beans and protein (pork or tofu are my preferences); if you have a big skillet you can cook that and something else on the side for 4 meals (dinner and then lunch for you and your dining buddy). You can experiment with seasonings to your liking, and add some variety by picking seasonings (ginger, spices, soy sauce, etc.) from a variety of regional cuisines.
Could also go for some pemmican, premade or made ahead of time.
(Conversely, what do you have as a handy low prep widely available lunch in the low-carb world that doesn't involve bread or pasta?)