Making bread is chemistry AND alchemy. If you don't knead enough, you don't get the gluten that allows the yeast to "grab" the fibers together which is how bread rises. So if the bread is LOW gluten (which many breads are these days) you won't get bread that rises well (you can actually BUY gluten to add to bread to get a greater rise). Also, where you live can affect your rise. I couldn't make decent bread to save my life beachside - I've been making bread BY HAND since I was 5 years old, and could not get the damned stuff to rise. Once I moved inland, I was once again a bread maker. Salt is also very important in the rising process.
So yeah, the quality of the ingredients is important, as is the physical reaction (the kneading - BuddyRoo - I LOVE kneading as well). In addition, sometimes breadmakers will control the heat excessively (they will run "hot" to force a rise). You can do this yourself by turning your oven on low and putting the bread to rise on the oven with a towel over it. But be careful - it can get too hot!
This is what I mean when I say that I prefer making it myself - I need to watch and see what is going on - how does the bread feel as I'm kneading? You add flour by feel to get a dough that is the perfect consistency. If you get a batch that isn't rising quite enough, you can use the oven trick to get a bit more rise, or when you punch it down you can just make italian bread (depending on the recipe) which doesn't require as much rise anyway.
I love making bread and giving it to my friends, especially.