Yeah, destroying pedestrian and cycle infrastructure to keep cars out is a pet peeve of mine. It's often dangerous, makes the path inaccessible, and just plain ugly.

Like the "concrete pigs" you mention. Often not marked properly, and cyclists have to slow down to a crawl to pass. Often 90% of the road is blocked with a boom barrier, and pedestrians and cyclists all have to share the remaining part to squeeze through. That only increases conflict. Also pretty hard for bigger cargo bikes, wheelchairs etc to pass. During winter, the booms are opened for the snow plow and then closed. Which means that as a cyclist I still have to cycle around on the un-plowed part...

It's insane the lengths one has to go to avoid cars destroying everything.

Edit: An example pic https://imgur.com/a/FmDd5Ve Nice wide road, have to close it off with a boom because of cars. Pedestrians and cyclists have to pass on the icy parts...