It all depends what the word 'Family' means.
We are family - or at least like family. We are now at a stage where the trust (In this business) is so deep, even if someone did something wrong, we would work with them to resolve it. (Pretty much like a family should).
Family businesses can be very stinted - with people expecting positions, promotion, and raises based on relationship over performance. I personally feel it is best to treat everyone as though they were family, but to never directly employ family - unless they have direct ownership with you. Familiarity can breed contempt. This differs when you 'need a hand', cleaning, making brews, catering, painting, shifting, etc. Family is great for this.
Anyways, I'm being cryptic. To answer your question, and the above stats, I can easily believe them.
Proffesionalising the Business - has to be leader led, with group co-operation. If the leader isn't trying to achieve this, and one of the juniors is, it can all fall to bits or be undone rapidly. For example. Dad took the business over from his Dad, and now the youngest son wants to brand the company. But, this proffesionalism isn't wanted by Dad, because he's within his comfort zone and doesn't like change. There needs to be a mutiny of sorts.
Conflict Management - The times I've walked into a husband and wife business and you can cut the atmosphere with a knife is unreal. The angst can be taken straight home. Conflict Management is something we've only needed to address with outsiders here - being we've built a compassionate and caring environment to work in. When the conflict comes from the outside, there's a lot of support from the team. If someones having a grotty day inside these walls, instead of it turning into an argument, it just gets 'hugged out'. There's no way I could manage conflict if my parents worked with me.
Growth - Unless you're procreating your staff, this means bringing in outsiders. That can bring trust issues. Growth from just family means you cannot possibly have the best staff on board.
Company Succession - If the company is a great place to work, then why not pass it on to the future generation. But, I think some people may not want to lose control - it is a marker to say you're getting old, so Succession may be delayed, or not forthcoming.
I once went to a meeting within a family run company, in which their one and only employee was about to be slaughtered by the owners (Both brothers). I was there as an advisor, on the employees desperate request, because he felt they wanted to get rid of him.
It was two hours of the brothers contradicting each other, and the stronger personality name calling us 3 others in the room. (I got called 'Spekky' and 'Four Eyes').
The long and the short of it was their business wasn't going so well, they wanted to get rid of this member of staff to save £1000 a month, and they couldn't do it effectively, so were trying to get him to resign.
In this instance, this was a company run by two brothers, which they had inherited from their dad. It looked a mess, the brothers were not good communicators, or managers, even though they lavished in the titles of 'CEO' and 'Director of Finance', and here we were in this quagmire of chaos which could have been resolved by having the right leadership.
If family business works, it works well. But, there are added disadvantages. It would be interesting to see the opposing statistics for non family run businesses with their plans for the above projections.