These numbers are meaningless. These aren't startup failure rates, but failure rates for all small businesses-- i.e. shoe stores, restaurants, etc.
And while the sample set probably includes very few (if any) software-based tech companies, I think there are more similarities than differences between the struggles encountered by two kids starting a tech company and two kids opening up a skateboard shop - bad hires, cash flow problems, finding customers, etc.
What am I not seeing?