Having owned and enjoyed many bikes with both types of frame construction I have noticed the compactness of the steel frame makes maintenence,servicing,and general access to most components of the machine much easier. All the new bikes offer amazing capability for the money , as well as being quite reliable for many seasons of fun !
I would be in favor of lowering the minimum weight rules to allow the continued improvement of the bikes ,as well as allowing the sport to progress into the future. Limiting some component materials could make cost sense as mentioned earlier in the post.