With regards to Notch Shelter, one of the biggest concerns with the increase in overnight use over recent years has been human waste, above treeline at practically 13,000' is not a place that can handle human waste on that type of scale. This was one of the driving forces in the move to officially close it to overnight use.
The shelter is also meant as a place that is available to everyone as a lightning shelter or place to take a quick break, if people are camped in there it gives other visitors a feeling that they are not welcome and impacts their experience.
I don't know what the enforcement or fine policy is going to be with regards to the shelter, but please consider these two items in particular and respect the closure. Thanks.
"We want the unpopular challenge. We want to test our intellect!" - Snapcase
"You are not what you own" - Fugazi
"Life's a mountain not a beach" - Fortune Cookie I got at lunch the other day