In some parts of the Netherlands and other parts of Europe you will see bikes on this theme. I had a guy in Paris at the weekend ride past on timber-sided long bike and we briefly chatted about where we were going. He was riding along quite smartly, thank you very much.
Maybe the length of the front structure might give pause as to what could be devised by someone with some imagination and skill.
The kids carrier shows a tent idea. And the bike taxi certainly looks to have potential as a caravan with fabric curtains to enclose the sides.