I think you don't get that one, probably because of the framing. I definitely don't think "don't talk to cops" is nuanced enough on it's own, but the perhaps US-centric part of it isn't the statement itself, but the context people will understand around it.
The core idea is that there are institutions in society (police being one of them) whose goals and incentives are contrary to your best interests. It doesn't matter that the people who work for them are "nice" or not, the act of performing their job can be very detrimental to you even if nobody involved actively wishes it. This observation is true.
I think the US part of this is that it's not some theoretical "don't talk to people who have interests that don't align with you", it's that actually talking to the cops in the US can never help you, only hurt you. If you incriminate yourself or lie to them that can and will be used against you, but if you make a good argument or have a good reason that will not be used in your defense.
By design, "anything you say can and will be used against you" which is a one way street.
The core idea is that there are institutions in society (police being one of them) whose goals and incentives are contrary to your best interests. It doesn't matter that the people who work for them are "nice" or not, the act of performing their job can be very detrimental to you even if nobody involved actively wishes it. This observation is true.