You have to remember that lots of people don't want to eat salad, vegetable based meals, avocados, lean protein, 'treat themselves' with a couple of squares of dark chocolate and they don't want to spend ages planning meals and cooking from scratch all the time.
Many people want to lose weight and still be able to eat snack food, chips etc. Suddenly stopping all this and switching to MN approved massive salads will be such a big change that they'll probably never do it. So the plan has to be attractive to them too.
And you never know, they might start to realise that eating more veg and salad and making 'processed crap' a much smaller part of their diet, or even eliminating it completely, will help them stay at a healthy weight without 'being on a diet' and even improve their health in general.
Hopefully all the current talking about the dangers of UPFs is going to inspire people to change, but while we have big powerful businesses pushing it in front of all the healthier food, it's very very hard.
Someone posted the other day how they wanted to buy ready to eat food while out and about and it was very difficult to find something that isn't UPF. Because all the bread is, as is just about everything else. You can sometimes get a prepared salad/protein bowl type thing in somewhere like M&S, but it costs twice as much as everything else and is often quite small, so not very filling.