Because some things are not for me, for you, for anyone, but exist independently. Are absolute, not relative.
Situation when a card is in hand, is one of circumstances when the card does not give MPs (to anyone).
Term "marshalling points of cards" is one of such absolute terms.
Otherwise a phrase:
A Wizard player does not receive marshalling points for defeating a creature with an "*" next to its marshalling points or for defeating a detainment attack.
could not be even expressed. (WTF is that ' "*" next to its marshalling points'? If the card cannot give
me any marshalling points, then there are not any MPs of card, even such that I could not receive [loop and vicious circle]).
"Geann a-Lisch is
![Ruins & Lairs [-me_rl-]](./images/smilies/me_rl.png)
for Balrog player" works like (limited to Balrog player's copy) errata. It changes one normal to other normal. Alternative to issuing Balrog version.
Still someone may say that a card that has its marshalling points is not necessarily "marshalling point card".