I doubt my position is typical for much of anyone, but my biggest obstacle was the difficulty in establishing an on-device build environment. Now since all the other platforms have cross-compiling SDKs, this is clearly more of a *n*x user's perspective than a mobile dev's, but as lma mentioned, we've got a platform rather like a typical GNOME desktop, so perhaps this perspective is slightly more broadly represented among prospective developers?

OTOH, I never tried scratchbox, so I'm not saying it's bad; just the expected hassle of getting everything working right kept me from ever digging in and doing it. (I do hope Fremantle will be nicer to on-device work -- there's absolutely nothing about the N8x0s rendering them unsuitable for moderate dev work, and even less about a new OMAP3 powerhouse.)