I was with you until here...
Actually, after reading it I don't get it either-- was quoting from a book on theory (work in progress) and perhaps the visuals would clarify (interactive book). I'd probably just disregard that last part, as the clef defining pitches is the key (so to speak): f and g count off or visually familiarize from there to read the staff.
I think it's a matter of accepting the notation rules as they are-- like realizing to write japanese means to go vertical with characters rather than letters.
but to answer the OP's original question: 'Why are the clefs taught in such a confusing way?' I think really
pssst! over here
be very quiet about this, but-- it's so that music teachers can have a job. It's like priests: you have access to the same holy book as them, but only THEY can tell you how to read it.same trick as all ways,
fnord!