Uppercut, I wonder, are you familiar at all with the statistical tool of significance? I ask because you maintain that even if having an extra mark makes a difference in only one in a zillion games, then it makes a difference and they should therefore be eliminated altogether or made available to everyone. The problem is, something only making a difference in that one-in-a-zillion is that it is not statistically significant. While I understand why you personally take umbridge with people having access to them, the statistics do simply not back up your claim that they make a significant difference in the game.
As a corollary to this, one could argue that the shards, nymphs, and even rare weapons should be removed due to the fact that not everyone has the same access to them. I think you could make the argument much better that they sway the game much, much more than marks because (1) More people have them and in greater quantities, so they will obviously effect the game more and (2) They simply DO more.
I'm not trying to attack you personally in any way, shape, or form, but I'm afraid what you are arguing simply does not have the statistics to back it up.