It's not true of most other aviation pioneers, because they were either independently wealthy or well-funded. The Wright brothers were self-funded but not really wealthy, their flyers were their path to wealth so the secrecy was understandable.
"most other aviation pioneers, because they were either independently wealthy or well-funded"
Wrong! One of them was Traian Vuia, struggling with financial difficulties which significantly delayed both the plane development and its final public demonstration in Paris! Other not so wealthy pioneers are Percy Pilcher, Lawrence Hargrave, Samuel Franklin Cody, Otto Lilienthal, Aurel Vlaicu, and many others.
