You’re probably right; the manga audience simply doesn’t show up in sufficient numbers, but that’s at least in part the fault of the festival itself. Despite a number of fine exhibition efforts and guests, their treatment of manga has been lacklustre for years. Condemned to the bottom of tents, or to tents off the beaten patch, the publishers haven’t exactly been encouraged to show up. And yes, the Manga Building sucks. I hope that the new Museum space will also be used for Asian shows in the future; for all the great things one can justly say about it, its presentation of Asian comics is, to say the least, lacking.

I definitely agree with your last point too: many missed opportunities. But that’s no different from other years — time simply disappears when you’re having fun. We were bummed we missed you on Saturday night. Oh well, there’s always a next year!

Regarding manga, your intuition is right: manga publishers (and to be honest, fans too) feel that Angoulême is not a place for them, and prefer to focus on Japan Expo as a key venue. Thinking about it, it is not surprising, since I feel that the Angoulême Festival ends up attracting mainly affluent adults (travel and lodgings being an issue) rather than the adolescent crowd that constitutes a large share of the manga readership.
Yet, the Manga Building usually tries to present a wide selection of talks and shows, which have nothing to be ashamed of when compared to the overall offer on the Festival. In fact, it is the available space that is the most problematic, as it means that one of the main exhibition (this year, Mukimura’s work on Vinland Saga) ends up being hanged by the toilets.

And I’d add another complain: how difficult it ends up being to meet up with people. I’ve brushed by many of them (including the Metabunker posse) on my way to something or other, and despite promises of hooking up later on, I ended up leaving Angoulême with an enduring feeling of missed opportunities…