As others have said, the Miqo'te markings are part of the race, plus their is one facial option without markings.

Taking this away would 1) take away one of Miqo'te's unique race trait, and 2) would be very hard to implement due to the usual PS3 limitations, character data limitations etc.

I'm all for more character customisation but you're not forced to have the markings. If they could remove them from face shape (like we'd like for the Au Ra horns) it would be nice, but highly unlikely.