Well, the gen ain't over yet and we have had plenty of others on this list that haven't made it like:

1) DriveClub 

2) Knack (I actually loved it) 

3) Destiny 

4) For Honor 

5) ARMS 

6) Quantum Break 

 Secondly, this generation isn't over yet. We still have games coming like :

1) Dreams 

2) Detroit 

3) new Super massive game 

4) Wild 

5) Anthem 

Then are the ones you may not count that are Indi'ish such as Resogun, Alienation, NEX Machina, Cup head etc 

Then are the big F2P games like Warframe, Let It Die, Drawn 2 Death. 

Having said all that, it sounds be interesting to see a tournament where we put the best games of last and current gen and see who gets the most points. 

Yes it did do something right, it released on a console that has very few games worth playing. And almost no multiplayer shooters to choose from.

Then why didn't that help other games sell better than what they did? Why didn't Xenoblade Chronicles X sell more than it did? Why didn't Pikmin 3, especially since it released early in the console's life when there were even less games. How about Hyrule Warriors, Bayonetta 2, Donkey Kong Country Tropical Freeze, Captain Toad, Yoshi's Woolly World? I'm not saying these games sold horribly, I'm just saying Splatoon vastly outperformed them. Even Super Mario Maker sold less than Splatoon. Why didn't these games, which were on the same console that had very few games worth playing, sell better?

Just accept the fact that Splatoon is actually a great game and that's why people bought it.

None of those games you mentioned were good barring Bayonetta 2. I'm guessing Bayonetta was too mature for the Nintendo audience, and not because they're all kids I happen to know that most people who still care about Nintendo are pretty old as far as their age goes.

None of them were good yet most had higher metascores than Splatoon? Does the metascore all of a sudden not mean anything now, because it meant something when you were saying Splatoon was average and the 81 metascore proved that, even though an 81 is actually pretty good. So I ask again, why didn't those games, which were on the same system that didn't have many games worth playing, not sell better than what they did? 

Also, you really didn't have to take that jab at Nintendo fans there, but I guess it's all you could do if you couldn't actually give a better argument. Oh well

Splatoon has outsold Horizon and blew it's attach rate away. If anything, there's a Sony bias.

Horizon Zero Dawn has been out for only a few months, It had sold 3.4 million in two months. Splatoon sold 1.5 million in it's first two months.

Also no one cares about attach ratio, it's more than evened out by the fact that Nintendo consoles have very few games to choose from in comparison to Playstation consoles. Look at the over all attach ratio of these consoles PS4 has an attach ratio of like 8 while Wii U had an attach ratio of less than 6.5, the sales on PS4 are jusy spread over way more games, while on nintendo it's usually the same few titles selling great while everything else gets ignored (usually cause everything else is beyond terrible). According to VGC there were only 21 games that sold a million or more units on Wii U, while there are already 98 on PS4 and will likely be like 300 million seller by the time this gen is over.

GTA SA had a massive attach rate between launch an a year after on a console that sold more than PS4. If a game is great enough and there is enough demand, the attach rate will bear that out. This argument that there are just a bunch of legendary games causing buyer fragmentation is ridiculous. 

What, no love for Knack or The Order 1886?

I'm voting Other, because I haven;t played any of the games on the list, but I have played The Order 1886, and it was pretty good, with flaws.

Probably switch to Horizon: Zero Dawn once I play it.

Bloodborne really only gets the "New IP" title on a technicality. It's really part of the Souls universe so I personally don't call it a gen 8 new IP. But that's just my opinion and I have no problem with people having a different view.

Does Star Fox 2 count as a new IP since the Star Fox brand is dead and it never came out before ?