"Is there something inherently offensive about the idea that you're struggling because there's something you haven't learned yet? That a T can either provide that missing information or discover it with you or help you find it on your own?"

Yes. It starts therapy off with a client=broken/therapist=savior approach.

One may learn things during therapy. I have learned one or two myself. But the idea as you phrase it suggests deliberate instruction, like the therapist has a syllabus and a lesson plan for the client. The learning should be incidental, like an insight you have when reading a great novel.