I do care about the illegality of Cloud's Rest assuming that is the rule. I received very clear info on this forum (find the thread if you wish) that indicated it was acceptable assuming good weather, same on other forums, plus when we gave rough itinerary to Rangers getting our permits they did not say anything. The Ranger after the fact was the first who very clearly told us it was out of bounds. We asked about it and he explained it clearly. I would not do again and I would not encourage others to do so. I posed the question here given the very mixed info received from variety of sources, I was curious what others may say. I am still grateful for my an amazing night and will leave it at that.
Water - I will almost never drink straight from the source; not a risk I want to take. My filter was like new with maybe 30 liters under its belt before the trip. Thankfully backcountry.com is taking it back since it seems to be a warranty issue. And I intend to simply replace w same filter because I love the system. Plus I will continue to bring a backup system of some kind as well.
The thing is, the rangers don't even agree on the rules in the park. I generally assume that if the peak is popular, there will be a ban on camping on it -- the goal is to facilitate public use while preserving the wilderness and that's pretty darn hard to do, as we all can see, and there are similar issues in Sequoia and Kings Canyon -- there is for example nothing posted anywhere about whether one can overnight on Alta Peak. One year, we got a permit and the issuing ranger was down with it -- no problem. The following year we were chewed OUT, big time, for the plan to spend the night in the light of the super moon on the peak top.
I think it is hard to see the consequences of our actions in these matters -- we are but a handful of backpackers and pass through these spots one group at a time, without awareness of the thousands who have gone before or come after -- the rangers who patrol have the best awareness of what's really going on, and they aren't able to address everyone who goes. Rangers behind desks have different ideas of the rules. Some are volunteers. I have corrected rangers at the wilderness office in Yosemite when they are dispensing blatantly incorrect information -- also camp hosts. The host in Bridalveil campground insisted that bear spray was "okay" -- it is most definitely against the regulations, which can be read on the website, but the paranoid hiker was of course going to believe the host instead of me.
Things like camping restrictions are not always written down, so I don't wonder that they are not clear to everyone. And many are going to think asking forgiveness is preferable to asking permission, or are just going to do what they want anyway, because they really don't give two figs about those fragile ecosystems, they just want their vacation the way they want it, who cares about anything or anyone else. I'm glad to hear you aren't one of those. I try not to be as well. It isn't a popular stance, but I tend to view public lands as a public responsibility, which is not at all the attitude of so many others who think "my tax dollars paid two bucks of the park budget, therefore I can do what I want out there without consequences."
As for water -- yeah, I filter/treat/boil all the time. Another thing people like to assume. I know too many who've had Giardia to not be careful.