Why? That's where the answer is, not in the opinions (educated or not) of SGOTI. Read it again. Really. Don't start with the assumption it is not understandable. Here its is... all of it that applies to logging PIC time. If it ain't there, it ain't loggable (except for definitely one and maybe two special situations that have nothing to do with your question)
61.51(e) Logging pilot-in-command flight time.
(1) A sport, recreational, private, commercial, or airline transport pilot may log pilot in command flight time for flights-
***
(2) If rated to act as pilot in command of the aircraft, an airline transport pilot may log ...
(3) A certificated flight instructor may log pilot in command flight time for all flight time while serving as the authorized instructor in an operation if the instructor is rated to act as pilot in command of that aircraft.
Does that apply to a student pilot? Does anything in 61.51 talk about student pilots? Well, there's this:
(4) A
student pilot may log pilot-in-command time
only when the student pilot -
(i) Is the sole occupant of the aircraft or is performing the duties of pilot of command of an airship requiring more than one pilot flight crewmember;
(ii) Has a solo flight endorsement as required under § 61.87 of this part; and
(iii) Is undergoing training for a pilot certificate or rating.
Can you answer your question based on that?