He doesn't need to know you to be surprised by your point (b), which would be possible to work out without buying the thing. It is surprising. It is similar to

He doesn't need to know you to be surprised by your point (b), which would be possible to work out without buying the thing. It is surprising. It is similar to someone buying a Porsche and then returning it because, among other reasons, it is a fast car. This is something you know before buying it. To return it to the dealership, saying "I don't like it, because it is fast", is quite surprising. Now, if you didn't know it was just another media consumption device - perhaps you thought you could also do some serious work on it - that would be different.