Man people get a bit too invested in what others they don't know or will ever meet do. This user no doubt had more Olajuwon cards than me too but I honestly couldn't tell you.
Best lesson I ever learnt in life - and I am glad I learnt it early - only care what your family thinks. For everyone else in the world just be you and do you and they will either accept you or not.
I would never let anyone else's actions/opinions/collection reduce the happiness I get from my own.
And, yes, the behaviour of this member seems strange but if they want to make a made up list because it makes them feel good or for any other reason then so be it. As long as they are not trying to sell/trade the cards they don't have then I don't care.
Of course if they were to move them all to For Sale/Trade and start fraudulently trying to move them then that is a whole different story.