"All of what you wrote indicates a distinct lack of planning."
No, it really doesn't. Take a situation where I am working late at an office on some important project for my employer. The office may not have an available oven, and I'm unlikely to carry a toaster oven with me on the odd chance I choose to use it. The office kitchen won't happen to include all the ingredients for pizza. If I tried to bring all those ingredients with me, some of them would be damaged or spoil. And, if I'm working late at an office, I likely don't have the time to fully make a pizza. Even if I knew all this would happen, there's not a lot I could have done. Most often, when something like this happens, I didn't know I'd have to do that until I was already there, preventing me from planning anything before coming into the office. I could of course run down to a grocer, buy the ingredients, and make a sort of pizza with the office microwave, but it will take longer and produce an inferior result than going to a restaurant and bringing one back.
Your argument works great if you're in your own house or the house of someone who doesn't mind you using their stuff. I'm guessing that, like me, you're in that situation a lot these days. Now that I'm working from home most of the time, I get the chance to cook many of my meals using my own equipment and ingredients, and I enjoy doing so. There are times where you're not at home, and things are different then. On occasion, some of those situations also apply at home. This office example is not the only one where that applies, but as you appear to have an investment in not accepting this, I'm not sure listing others would help.