We can't possibly know that solely based on (what other comments have rightly pointed out) a vague, anon petition lacking nuance or details. This could just as well be a very small, vocal minority. We have no way of knowing without more information.
One of the stated goals of the no-politics at work stuff was to allow Coinbase staff to "Support each other, and create team cohesion". It doesn't look like that has happened!
How do you know? You can't deduce this from one post.