I think its more like going back to the initial spirit of Scheme and making it right: "Programming languages should be designed not by piling feature on top of

I think its more like going back to the initial spirit of Scheme and making it right: "Programming languages should be designed not by piling feature on top of feature, but by removing the weaknesses and restrictions that make additional features appear necessary." So, criticizing lack of features is meaningless to Arc. Valid criticism may be to find weaknesses and restrictions.