This ‘protip’ is quite wrong on many levels. Observe the behaviour of the most successful investors, and you will notice they write books, go on podcasts, talk about their strategies etc all the time. In fact you can’t shut them up. The world’s most successful investor, the biggest ‘Scrooge McDuck’ of them all, has completely public disclosures.
On the contrary, the worst advice comes from people who have no accountability or reputation to worry about.