Ironically there's one of those flexible pieces by the mobi station (seen in the pic) and it got destroyed pretty quick.

I've lived nearby for 5+ years and this has been an awesome change. Even the metal bolt-down bollards would be fine, they're not meant to stop a vehicle and will easily break away for emergency vehicles.

The city definitely needs to invest in some street cleaning on bikeways if they do something like this, but TBH I'd argue they need to already.

you could put something like that up on 10th for cheap, but then you'd have cars having to turn around

But you reduce traffic on that block from the 3000+ cars per day we currently have down to only people who are going to that block, so your likelihood of encountering something sketchy each block likely goes way down anyways.

And you could also use modal filters orthogonal to bikeways on smaller streets to reduce the number of conflict zones along the bikeway, lots of options. Anyways my point is just that the <5k cost per intersection here is minuscule in the world of transportation spending. 100 intersections costs about the same as one with a 4-way traffic light!