Because in the case of the former I find it unbelievable that no one on the team, or even at Volvo that dropped by to see how the project is coming along (I assume they weren't shipped off to some isolated island to complete their work in complete secrecy) didn't say something. The first question at least 80% of people I know would have when looking over a car to buy for the first time is, "Can you pop the hood?" Not to mention getting at the engine to adjust or replace consumables like belts, fluids, plugs or even minor repairs.
I'm far more willing to believe this is just a small detail that simplified the production process for a one off prototype than that anyone thought this was actually a good idea.