I'm certain that RB, David and Sarah wouldn't have put their own capital into a business run by utter muppets - and there is obviously nothing wrong with investing in a business concept that you think has potential.
What I strongly object to though is dragging us all along through the farce of a competition whereby the weekly challenges and outcomes were seemingly irrelevant to the final decision. I can see why Chris, Nathan and the other couples weren't an attractive proposition as business partners - but you can't shoehorn a contrived load of old guff into a popular programme format and expect the viewers to feel like they weren't being totally patronised. Piss poor.