Actually, it's kind of obvious. He gets a wonderful vacation place. His trophy wife gets "meaning" in her life, without any heavy lifting (of a pen, to write her own book, even). Contrast the Imus ranch with the real charities cited in the article. It is easy to see the difference.
A vacation surrounded by children in various stages of an illness that eventually kills some of them is a "wonderful vacation?" Just the psychological stress of working with these children every day, while insuring that their medical needs are met, isn't something most people could handle.
I think a "trophy wife" is a young woman a successful, married , older man, dumps his longtime wife to marry in order to enhance his male, conqueror image.
Imus had been divorced for many years when he met his current wife. We don't know these people so we don't know if they "get meaning in [their lives] without heavy lifting." Actually, I can 't imagine judging the motives of people I do know when considering their charitable activities.
There is a difference between other charities and the Imus Ranch; they are offering a different concept of helping these children. It doesn't make the Ranch any less a "real" charity.
I wonder if the kids get to use the Master Bath outdoor shower designed to look like Aztec ruins.