This is a clear example of miscommunication.
Banning all cars from the bridge was not meant as a serious proposal, but just to show that these people do not care about pollution at all.
Meanwhile, you seem to have taken that proposal as serious and that it was calling to ban cars everywhere, instead of just one bridge. Banning cars everywhere is a fringe opinion even here, and I think no one ever suggested you have to "move stuff" with cargo bikes and public transport exclusively. On top of that, I personally don't quite agree with the way you said public transport is "underdeveloped". Yes there are specific addresses you can barely reach pretty much everywhere, but you comment reads as any specific address can't be reached. I think we can expect people to walk a few hundred yards to a bus stop.
Wrong thing to say at the wrong place, do better next time.