Phil, your argument is that they should have taken one shared MLU or PLB with them to minimize the risk to SAR, right? Instead they brought a cell phone.
For argument's sake, let's pretend they did bring an MLU/PLB instead of a cell phone. What do you think Brian and Nikko would have done with the MLU/PLB when they left Kelly in the snow cave to get help? Of course they would have left it with him. Duh.
Which would leave SAR in EXACTLY the same position as they are now. They know Kelly's location but cannot reach him due to the conditions near the summit while they have no idea where Brian and Nikko are hunkered down.
And actually, now that I think this through further, the phone was more useful than an MLB/PLU. If they had brought one, they likely would have left the cell to minimize weight. When the beacon was turned on, SAR might have assumed they were together and only focused on reaching Kelly's snow cave. The cell allowed Kelly to report that they had separated AND provided SAR with his position. When SAR finds Brian and Kelly, that cell phone will be the reason.
On a side note, what kind of tool wears a life jacket while boating?