Hef donated almost a million dollars to save the Hollywood sign. It wasn't in danger of falling apart - it was refurbished in 2005 by the Hollywood Sign Trust. In fact, the sign was brought back from its nadir in 1977 by an effort Hefner led. Seems like he feels personally responsible for the sign, and that's fine. They didn't just save the sign, they bought up the area around it:

The sign will be saved from development, because it's history.

Amusing part: the sign was originally built to advertise a development, in 1923.