BB have deliberately made a distinction between Marcus and Siavash and the rest of the house.
EVERY HM should have been given the dilemma of giving something up about their character until BB finished if that was the way they were going.
It's so blindingly obvious that BB intended them both to say "NO" when offered the choice as this would make them look bad.
They have focused in on the two most obvious character traits of Marcus and Siavash that are most important to them and then made a choice to strip them of them.
Don't hold your breath that the others will have a similar situation.