Greetings!
Well, there were actually several reasons for that.
First of all - safety first. There are some legal regulations and here in Europe it is not that easy to do a van conversion and simply hit the road. If something bad would happen, you might get yourself in huge trouble. Police and insurance company especially would have a big issue with that. In such a case they can deny any insurance pay-off and you can imagine how expensive it can get if you consider the damage on vehicles, property or even health. So as I mentioned above you need to make sure there are no sharp edges, everything is anchored properly etc. So this is most likely the biggest issue we needed to face to.
The other reason is that we needed as many storage space as possible and we definitely wanted to have the pull-out kitchen cabinet in there. Considering the very limited space in the car, we needed to put it right behind the driver’s seat.
On top of that we had a requirement to have 3 seats in a front and there is no space to walk through to the back anyway.
That’s pretty much it 
Does it answer your question?
Cheers!
Luke