Because you can get better return on your spent dollars on other credit cards. Thus, you're giving up higher cashback or equivalent purchasing power credits on better cards out there for what? If you're taking 2x points on gas on the Mlife card and I'm getting 3x points on a better rewards card, then youre only getting tier points to show for it. Otherwise, you're giving away money. This, you're paying for tier points. As an example, if my Chase Freedom were giving 5x points on gas this month and I spent $300 on gas, I would earn $15 in cashback. If I spent that same $300 on the Mlife card, I would have earned the equivalent of $10. Thus, I just paid $5 for the tier status points, because that's all I'm getting for that $5 loss in reward equity.