In my experience with teaching, many students do not practice, especially those who are relatively "new" to lessons. I think this is because they sort of view the lesson as the practice time, they will somehow learn by osmosis. You see a similar thing in schools today, at least here in the US. Any homework is more about busy work than encouraging creative answers to acquiring new technical and expressive skills. In music that becomes even more important.
The Suzuki methods generally are geared towards younger students, there often is a cut off for how old one is when they start. In my main school it is 8 years old. I think there is the idea that one needs to have the child in "the method" before their "thinking" brain comes on and starts over-analyzing everything, positively to get them in the habit of "listening" more than analyzing/reading. Personally, my read through of Suzuki made me think of a lot of new agey stuff, but there are also some good things to be learned. "Nurtured By Love" is the classic that is required for parents to read when they are starting out. I must admit that the best students though never come from Suzuki backgrounds, and those who have studied Suzuki often have serious technical problems later on down the road, and are poor readers. That doesn't mean you shouldn't grab a few of his ideas.
I wouldn't take it personally that he is not entirely interested, it is good to observe this but I think you should be patient as well. If he seems to have a positive attitude but gives you vague answers, maybe let it be for a bit? You never know when a student like that all of a sudden is going to hear a piece and be totally thrilled by it, and want to learn it. In the meantime they have VERY SLOWLY been acquiring the skills to play this piece, even if it seems like you are going at a snail's pace and only are getting work done in lessons.
I would highly encourage a listening component to the assignments for the week. I have found this particularly effective with inner city kids who are in programs I teach at because scholarship funds it and their parents (or teachers, or the kid) thinks it's a good idea. These kids often have so much other stuff going on in their lives that the last thing on their mind is which song they want to learn. I like to do this as a journal. I usually say, pick one song you heard on the radio, youtube, whatever. Say what the song is, who wrote it, etc. What you liked and didn't like about the song. If you hated it, that's ok. If the only music you heard was on an elevator, that's fine too, just write about it and think about it. A lot of kids start out not doing it but after some encouragement they start to get excited about it. The nice thing is then you can sort of steer them towards genres/appropriate songs, some of which they might not ever have encountered in a traditional method. With guitar you do have a lot more freedom in styles than say, oboe, of course! ;)