HDTV market penetration is still only at 46% in US households but yeah if you looked at households with gaming consoles, especially HD gaming consoles (PS360), I'd imagine that the penetration would be a good bit above the majority. And then take into account PC monitors. My guess is even if EA could fix the issue at a low cost, they're not gonna bother. Mass Effect is probably quite profitable for them as it is.
It is true that a lot of game publishers have lost money going HD but that's because many of them have a habit of investing huge budgets into titles without the revenue potential they need to support those budgets. It's not a SDTV thing. That said, I'm sure that the Dead Rising debacle probably cost Capcom. In early 2006, HDTV market penetration wasnt there to the same extent.