My hunch is that the main problem is that the dishes both just get briefly sauteed rather than, say, baking for a while. I don't know whether baking these dishes is more authentic (yes, I know better than to buy cookbooks aimed at Americans; this was a gift--from an Indian, even), but it seems like it would deepen the flavors better than sauteeing does.
Regardless, can anyone point me to a good, richly flavored baigan bharta and/or channa masala? I can get all of the ingredients at the farmers' market right now (even the chickpeas!), which makes me eager to achieve better results.