For pedestrians and cyclists closing access points is undeniably a benefit. It reduces the number of potential conflict points where a vehicle can cross the sidewalk or bike lane. For the cyclist, this permits higher speeds and better safety. For the pedestrian, it permits greater attention to be devoted to the surrounding environment, which makes for a much more pleasant walk. More window-shopping, less dodging cars.
But what goes along with access control is frequently higher speeds along the road. Less of a matter if you are on the sidewalk, and protected by the curb, but for a bike trying to stick to the shoulder... very nervous business.