the fire has nothing to do with the amount of people visiting but is due to people's stupidity.
Less people = less people who are likely to make a stupid mistake.
I can understand that they try to keep it pristine, but i've seen other places in the world do it with 10 times more people
Again, its up to the individual parks to decide what they want to do. If CONAF wants to limit the amount of people on the W and the Circuit, then they can justifiably do that. Just like if Los Glaciares wanted to limit people who camp or enter the North section, then they can. As I hear, they were thinking of implementing a entrance fee for that section of the park.
The examples you give seem to be places where the numbers are far higher than the 30 or so daily hikers allowed on O loop.
They are still examples of places that choose to limit the amount of visitors. It also allows it to be a much more peaceful experience for hikers.
But yeah, i get the reason, it just doesn't make sense to me that this side is limited to 30 people while the other one received hundreds. That's all.
The campsites on the W are also limited as well. There might be more on that side, but they're still limited in capacity.