1. People in their 30s tend to have children. I started earlier than that, but a lot of people wait until then to grow their family. Also, 30s is not considered retirement age for most people, so they tend to go camping on the weekend, as they have to work Monday through Friday. I hope I've shed some light on one of the universe's most complex mysteries for you, OP.
2. You might want to sit down before reading this, OP, as it could possibly upset you: other people might like and do things that you yourself do not like or do. These things could possibly include making a fire during a brisk 40 degree day or using an awning during daylight hours. I'm guessing you might be a werewolf and use your awning exclusively at night to block full moons, but overall, using an awning is fairly common, even during the day.
3. Regarding outside kitchens: this comes down to "stop liking what I don't like!" You might not see the need or enjoy what they offer. However, other people might think differently than you do. Don't worry though! You still have the option of not having one. Conversely, other people have the option of having one. The ability to make the choice to have or not have something that you like or do not like is called "freedom", and it's kind of a big deal in the USA. 'Murica!!!
I hope this helps!
Full disclosure: I hate putting out my awnings and rarely do, and I do not have an outside kitchen. However, my wife would definitely like a fire if it's cold out, even if the sun is shining and some old guy is yelling "get off my lawn!" while shaking his fist.