Of course those games have value, but they sell to people who already own a console and not a console to those who don't have it. And that's where Nintendo failed in 2018.

I understood that.  Like I said, I don't think we're far apart in terms of thoughts on the subject.  Where we diverge is that I believe that additional mid-tier titles keep the system sellers themselves potent.  It's not so much that the mid-tier titles sell systems themselves, it's that they provide a sense that the momentum is continuing so that if you almost bought the Switch for Christmas, perhaps you pull the trigger on your birthday in April or whatever.  Even if the big reason is still wanting to play Mario Odyssey and Breath of the Wild, you don't look at the system 5 months later and wonder what you gained by waiting.  There's a feeling, and some truth, to the notion that even though you waited, you're still getting a better console today than you would have previously.

Anyway, that's why I think it would have made a difference in terms of sales.  All consoles only have a couple of "system sellers" in any given year.  2017 was an exception.  The connective tissue is what makes the difference.

Yep, these "filler" titles dont move consoles, that's why it sold ~8.7 million from Jan-Oct.

Me too. It's been my most wanted game for years. 

If they move consoles why didn't HW sales showed that when they came out?
As i said above, of the 3 2018 titles i looked at, only DK caused a small boost. And it only lasted a week.

I'm not saying that it's irrelevant if those titles exist or not, i just don't see them as important in keeping the momentum for console sales.
They have served to create buzz and satisfy Switch owners, but that has been pretty much it, i think.

A game doesn't need to create a massive boost in order to move systems. A steady flow of desirable games can simply cause the momentum to remain stable.

Again, how could they sell 8.7 million units of hardware over the course of 10 months if the games released this year aren't moving systems?

How much would Switch have sold in those 10 months without Kirby, Donkey Kong, Mario Tennis, Octopath & Mario Party?

What you are saying makes sense. But i didn't say their existance was irrelevant.

I was merely talking about selling power, in a sense: to move to systems.
Thats's why i said this:
"This year, as the Switch situation has settled down, sales wise, it's pretty much as if those titles never came out.
The value added to the library hasn't really changed up things."

As in, if you want to push HW, you need more than this.

Yet, i still have to ask: if they didn't come out, would have Switch really take a hit? 
It's not as if we are in a Wii U situation where every game counts or Switch is in it's final years and these games are needed to keep interest around the console and help it not go down as hard.
Also, those game's sales account for less than 15% of SW sales this year (vgchartz numbers).

If i had to answer the question "Again, how could they sell 8.7 million units of hardware over the course of 10 months if the games released this year aren't moving systems?", i would say it's due to the hybrid concept, still big popularity and Mario 3D, Zelda, MK8, Splatoon (these 4 games account for a little over 30% of 2018's Switch game sales), around 1000 games and honestly, a lot of confidence in the console's future (quite impactful for a console that succeeded the Wii U). 

To me, they have done more in satisfying the userbase than actually impacting sales, as momentum is still strong enough for it to be held without Kirby, DK, Mario Tennis, Octopath (a lot of talk about a game that hasn't even sold a million) and Mario Party (i'm assuming HW sales didn't go up at all or significantly with this one. Haven't checked).
In a different scenario i'd probably agree that they had more weight.

I just checked, according to VGC Switch sold about 800k last October (the month Odyssey came out) and about 850k this year (the month Super Mario Party came out). Granted, Odyssey came out in the end of the month, but it's much more frontloaded than a game like Super Mario Party is. 

That said, I wouldn't say SMP is a big system seller or anything, just a nice evergreen booster.

What you are saying makes sense. But i didn't say their existance was irrelevant.

I was merely talking about selling power, in a sense: to move to systems.
Thats's why i said this:
"This year, as the Switch situation has settled down, sales wise, it's pretty much as if those titles never came out.
The value added to the library hasn't really changed up things."

As in, if you want to push HW, you need more than this.

Yet, i still have to ask: if they didn't come out, would have Switch really take a hit? 
It's not as if we are in a Wii U situation where every game counts or Switch is in it's final years and these games are needed to keep interest around the console and help it not go down as hard.
Also, those game's sales account for less than 15% of SW sales this year (vgchartz numbers).

If i had to answer the question "Again, how could they sell 8.7 million units of hardware over the course of 10 months if the games released this year aren't moving systems?", i would say it's due to the hybrid concept, still big popularity and Mario 3D, Zelda, MK8, Splatoon (these 4 games account for a little over 30% of 2018's Switch game sales), around 1000 games and honestly, a lot of confidence in the console's future (quite impactful for a console that succeeded the Wii U). 

To me, they have done more in satisfying the userbase than actually impacting sales, as momentum is still strong enough for it to be held without Kirby, DK, Mario Tennis, Octopath (a lot of talk about a game that hasn't even sold a million) and Mario Party (i'm assuming HW sales didn't go up at all or significantly with this one. Haven't checked).
In a different scenario i'd probably agree that they had more weight.