Every word, every sentence, and every paragraph of a good piece of writing has the potential to teach you something. That doesn’t mean that you shouldn’t be selective about what you read or that you can’t give up on something that isn’t speaking to you. What it means is that for something to move you, you have to be ready to be moved.
The point of reading isn’t to memorize, and it’s certainly not to critique. It’s to absorb and filter with an open mind — to find the right thing at the right time so that you can improve and update your existing model of reality rather than mold whatever you’re reading to fit into it as it is.