Actually Earthbound isn't a good example. As someone who had a SNES I never heard of that game until well after the SNES had gone. While it might have been promoted heavily to a segement within geek culture, it was NOT promoted properly to the demographic at large as I knew a decent amount about gaming at the time, was really into RPGs, both PnP AND computer oriented, and it was my kind of thing.
To be honest I think there is MORE awareness of Earthbound and Mother now than there was then.
Basically, throwing up advertisements and spending a lot of money promoting something is absolutly pointless if you somehow do it the wrong way, and it's not always obvious what went wrong.
To be honest I tend to think of Nintendo as being less stingy, than stupid.
Earthbound/Mother is in the same basic position as "Shin Megami Tensei", basically despite the promotion that was done with it, it managed to slip under the radar. The original SMT releases did not sell all that well, and got most of their following after the fact, which eventually lead to them trying again, and well... you can see what happened with the SMT titles becoming a pretty big deal in the US within the intended niche audience, which CAN sustain them.
Of course I suspect a lot of this comes down to racism as well. To be entirely blunt marketing realities aren't all of which drives the Japanese gaming industry. Years ago I used to be heavily into reading translated Japanese gaming periodicals to find out what was going on. One thing I caught was that there was an attitude that the Japanese, especially the fans, want to keep a lot of things Japan-only, and feel that it somehow cheapens the property to have an overseas release, especially to the US (which they have a wierd love/hate relationship with). Things like NOT releasing the "Final Fantasy X: International Edition" with expanded content and "Final Fantasy X-2: Final Mission" ending that story were NOT based on sales, but simply a desire to snub the US, some things I was reading were quite blunt about it.
This logic also influances why the US has not gotten numerous other games like the various "Super Robot Wars"/"Super Robot Taisen" games released more seriously here. There are claims that the liscencing would be too expensive, and similar things, but the bottom line is that there is a lot of pressure to keep them out of the US market. Selling to the US for more money is actually seen by some as "selling out". Now granted you might remember us getting some rather bad installments for the gameboy, and a more recent "Fronteir" installment which oddly enough didn't include any fighting giant robots and was more of a straight RPG (though it did feature Kos MOS from Xenosaga which was pretty cool I guess).
The overall point here is that with "Mother", I'm not entirely sure you can put the blame for us not getting futher games in the series at the feet of the fans. With the word of mouth and it making all these "best of" lists as a game many people hadn't heard of beforehand... well I'm pretty sure it could pull a SMT. I think there are a couple of differant reasons (mentioned above) we haven't seen it.
As far as "Scott Pilgrim" goes, I think there was some vast overestimation of the popularity of the property. What's more it was a movie made very specifically for a young geek demographic, rather than geeks in general. Kids by definition having less disposable income and the need to convince their parents to take them to a movie like that and pick them up.
I'm a huge geek, and really while I thought some of the ideas were interesting, I had no real interest in seeing the movie, so I didn't. It pretty much made my "maybe on Netflix, if I'm really bored" list, because really I don't associate myself with a teenager hipster douchebag doing a modernized retread of "Parker Lewis Can't Lose". Granted 15 or 20 years ago when I was in high school, or maybe early college, I would have loved this, at 36... meh.
Scott Pilgrim failed because it wasn't a geek movie, it was a movie aimed at a narrow segement of the geek community, that oddly enough have problems (especially in this economy) attending movies. Especially seeing as movie theaters over the last decade or so have tended to move to more isolated locations, as opposed to being say on the side of mainstreets. Most are attached to shopping centers, isolated from residential districts for traffic related reasons. This is also done specifically because movie theaters attract kids, and people in downtown or nearby residential areas don't want the rowdy kids around that they bring in.
While it was many years ago, one of the last few remaining theaters in an actual town that showed movies like this "Jewett City" was in part responsible for the town imposing a curfew on those below a certain age after a specific time. It was challenged and overturned, but well... that kind of summarizes the attitude.
Now granted there are probably areas that represent exceptions as far as theater locations, youth access, and similar things, but thinking nationally... well, I think there were problems with audience accessibility that were not considered, of course then again I also think they misunderstood who their audience actually was and how narrow a niche it was.
