I think both you and Tom are right here - the (many, present day) indiepop lovers of my acquaintance tend to be drawn to it because it offers an introverted and understated version of the emotions in lovelorn proper pop, for introverted/understated people. The social contract is there via the perceived accessibility of the artist/object of desire/identification. But the wider context of resentment and alienation doesn't have to be, except in the sense that favouring one possible representation = alienation from another (does it?). And you don't have to care about being part of a (global, scattered, online) niche of introverted/understated ppl either. The bands often hold out the whole indie package - imagine my surprise at the explicit political content of the latest My Little Airport record - but really, how many of their listeners care whether Donald Tsang lives or dies? Really?

Indiepop lovers of my acquaintance are also 150% more likely to listen to Annie than the VU. XD;

Why YBWM is not indiepop: because Taylor is the cheer captain these days to America regardless of where she'd place herself. But like Tom I enjoy her music because of that kinship.