You can use Firefox (or Brave) and still point out Google's privacy violations and self-dealing. These positions aren't mutually exclusive, and are more productive than 'stfu n git gud. git f1r3f0x.'

1.) Not everyone is going stop using Chrome. It's better to let Chrome users know what they're getting into.

2.) Pointing out Chrome's privacy issues gives an extra push to stop using it. This post may be just the push someone needs to overcome the inertia built by using the same program for years.