Ninja looting has its own risks, of course, but so does running a dungeon, and things can go wrong in dungeons just as easily as it can with ninja looting, via chain lucky crits, an enemy slipping by and getting to the backline or many other factors. The only added difficulty there is to ninja looting is that if something goes wrong, you are by yourself, which is something the suggestions try to tackle as a problem to begin with, and something the server design tries to avoid if possible.
As for it being a narrative and RP of its own, that is indeed true, and that is why the suggested changes try to keep that and improve it, such as the proposed spotter enemies and patrols, and increased lockpicking time. It is aimed at making stealth and ninja looting something more challenging and rewarding, and possibly even something that is a group effort, which keeps its benefits that were mentioned before but makes it something that is a group experience, and a unique one that regular dungeon runs do not really offer.
As for the lock DCs, I believe highest DC I have seen is 52 as well, but even that is the case for a few chests, I think the chests in the last room of Tomb of Hotep are DC 52 in the entirety of Har'Akir, perhaps the ones in the hidden room in Anubis as well but I think those are slightly lower. Even for higher level content, DC 52, which is not that high to begin with, is fairly rare. +12 lockpicks are a fairly common drop from Har'Akir, and they are excessive and hence useless for anyone with rogue levels who invest fully or heavily in Open Locks.
Going back to a previous point, Philos mentioned that there are indeed some very interesting RP opportunities that come up when you are alone and by yourself, and it is a great thing to have those. But I think taking the development in a way that benefits collective narrative and stories and increases RP between players is more important, as Soren mention in another post as well, and this may cause some frustration or some of these "isolation" narratives to suffer, but it would not remove it by any means, and I think a reduction in those for an increase in shared narrative is a worthy trade off.