Private company sold != NHS issues
While I don't particularly like the man, Jeremy Hunt created this company in 1990, stepped away from it in 2005 when he became an MP, and stopped being a director in 2009, but kept his shares. He has had no control over the running of the company, and even though he holds 48% of the shares, he wouldn't even have been able to stop the sale of the company.
It looks like he's done the right thing with this business, and therefore I'm not sure why this is being linked to his stewardship of the NHS? The two are completely unrelated. "The windfall has brought with it some criticism of his policies as Health Secretary", which just smacks of the politics of envy.
"Oh, I don't like the way he runs the NHS, and he's made some money, more money than I'll ever make because I can't get off my lard arse to create a company that employs people and provides a service people use, and so I don't think he should be allowed that money - even though he'll be paying tax on it which benefits the public. Now, where's my e-cig? Jeremy Kyle's about to start."