Earlier quoted context omitted.
If your accountants suggest that you take a single 5% chance deal, they probably skipped maths and statistics and you should fire them. It's the dumb as rocks MBAs that will go head first into the 5% chance deal.
I guess the reasoning assumes that you have multiple eggs in your basket. A 95% chance of failure is bad if you're pinning the whole business on it, but if you have a variety of 5% chance deals, then it can make sense to pursue them, which is basically what venture capitalists do.
This is only true if the probability distributions for the values of the individual deals are rather uncorrelated (or even better: stochastically mostly independent).