Just like many of the sportspeople who aren't in the country, even those who have left since the invasion, the majority of people who disagree with it are too afraid of the consequences for saying too much or saying anything against the Kremlin narrative.

As an example, a Nobel-winning journalist was assaulted by pro-Putin Russians in public, when he has even abided by the new laws.

Also, I doubt Putin's regime is more frightening than the risk to die in a pointless war.