Because if, say, a lot of people bought PSPs early on because "omg, playstation portable" and then lost interest and shoved it in a drawer or hacked it or whatever, they're not active buyers. The sheer size of the install base doesn't really mean much when it comes to established series, so I don't think we can assume that a series at its peak popularity would necessarily see a decline even if it was on a system that had declined over its predecessor.

And completely opposite to how they do everything else, Capcom always lowballs Monster Hunter projections. They "expected" MH3U to sell 1.2 million on 3DS. It sold about twice that much. There is no way they really expected MH4 to only do a little better than a port of an old game.

I don't really know what you mean by focus on the west. If they were focusing on the west, they'd put it on a home console.

Keep fighting the good fight.

You are correct about that. Going from the 6-year-old PSP to the 2.5-year-old 3DS did not dramatically increase first-week sales of respective Monster Hunter games. But that doesn't have anything to do with the currently not-quite-2-year-old Vita.

Aside from that, your first paragraph makes it sound like you think Monster Hunter die-hards don't want to buy a 3DS for Monster Hunter, and/or that the general Vita audience overlaps more with the Monster Hunter audience than the general 3DS audience does. Either of these may have some truth to them, but given the fantastic sales of the series on 3DS, they can't both be true -- otherwise sales would be significantly lower than the PSP entries. You'll have a hard time selling me on either of the proposed theories, though, since I have my own anecdotal evidence to counter them. It won't mean anything to anyone else, of course, but having personal experience with Monster Hunter fans buying a 3DS for it and with 3DS owners who have never touched the series before loving everything about 3 Ultimate makes me less receptive to the above suggestions.

If MH was announced exclusively to Vita, just like 3DS now, Vita could have sold better since launch and sales will be high, like this week.

We need to factor, also, that Vita with better library and better jrpg support than 3DS is still selling in the (very) low numbers, fighting against Wii U, which doesn't have a price cut in the region, yet.

So, I'm not 100% convinced about numbers been the same, for both HW and SW, but it would have been high.

errrrhhhh... ?

Well, it kind of does. I suppose it depends on why the franchise seems to have peaked. It has pretty much stabilized, so either this is basically how big it is and it wouldn't have mattered whether it showed up on the 3DS or Vita next, or there will be growth but it will be all in the legs. I don't want to draw any hard conclusions based on MH3U's sales for obvious reasons, nor are first week sales the end all, be all, particularly on Nintendo platforms... but I do get the feeling that just like Dragon Quest, it doesn't really matter where Monster Hunter shows up, as long as it's a portable. That is, that the franchise has a certain size and reach of appeal, and that's about it. I guess we'll see.

You could be right that showing up on the Vita next would have resulted in decline instead of the present steady performance, but that's something we'll never know.

Or they can both be true to varying degrees, although I wouldn't have phrased it like that. A Monster Hunter diehard is a Monster Hunter diehard. He's going to buy a blender if it plays Monster Hunter. But not everyone who buys a game is a diehard fan of it, and a certain amount of the audience isn't going to follow if it jumps from one platform to another. Nor would I talk about the Vita audience as it currently exists (because it doesn't have one, ha!); more like, the PSP audience which would have migrated to the Vita if they had any reason to do so.

But yes, those phenomena are bound to be present to some extent. The PSP guy who doesn't want a kiddy DS exists, or the person who had bought and played Monster Hunter because it was on a system he owned but he just doesn't care enough about it to follow it to a whole different system. Those people would be the audience lost by the move, and some may have been lost whether it had moved from the PSP to the 3DS or from the PSP to the PSV.

And what you say would also be true to varying degrees. That there are lots of people who bought a 3DS for Monster Hunter because they loved the games  on the PSP is fluorescently obvious. That some people are playing it for the first time because they only own Nintendo handhelds is unavoidable. These would be the people gained.

So far the net effect of the move seems to have been a push. Whether all of these factors just roughly balance each other out or Nintendo's larger, more mainstream audience will eventually end up manifesting itself in monster (no pun intended) legs beyond those seen on the PSP remains to be seen. But right now I just get the impression that this is about the size of the franchise and it would have sold roughly the same anywhere.

Though, honestly, I was making more of a general observation about why a larger install base doesn't directly translate into more sales rather than positing anything about Monster Hunter and the 3DS audience specifically.

can't sell more than current userbase

Of course, dear, but one must assume that if the biggest non-Nintendo franchise in Japan showed up on the system the userbase would increase.

1. not bigger than dragon quest or final fantasy
2. at best conjecture, at worst wishful thinking.

1. It has been over a decade since Final Fantasy did the kind of numbers Monster Hunter is doing now. Dragon Quest can probably match it with a new mainline entry but not with the spinoffs, remakes, and MMOs that comprise the present output and are eroding the brand.

2. No. At worst obvious, at best fucking obvious.