I'm fairly indifferent about this myself. On the one hand, I can see abccc's point that it would be good for marketing and even without substantial additional benefits, it could provide a point for some frequent flyers to harder to earn extra 'status'. Maybe just allow use of First Class check-in desks though not the first class lounges.

However, on the other hand, I feel that the airlines' frequent flyer programmes themselves are complex enough, usually with at least 4 tiers. As such, keeping the alliance status system quite simple with just 2 tiers, might be the way to go.