"It's always too soon to talk about gun control"

[hazard]

Perhaps I'm naive, but I would hope judges routinely put aside their biases and preferences while deliberating on matters of law.

That is the job of a good judge, and there's plenty of good judges. Unfortunately, in cases of politically motivated and/or corrupt governments judges routinely employ their biases and preferences while deliberating on matters of law. And yes, governments are generally supposed to be politically motivated, but there's a difference between 'I want to make this true and will try and make it so within the bounds of law and reality' and 'I want this to be true and it shall be true regardless of law and reality.'

And guns in the USA?

Guns in the USA and the politics around them are often the latter.