I don't understand why anyone would defend a strategy of going months and months on end without any big games to spur hardware sales.
PS4 is down almost 20% YOY with these numbers. RE2/KH3 will cause a spike but that likely won't be enough to arrest the downward YOY trend for more than a week or two.
We will see. Talking about "% down YOY" after a week and half in 2019 can't represent the whole picture in 2019. Let's wait and see. Switch was surfing the wave of the most casual month of all, which is December, let's see what happens when figures stabilize, and it's already happening. NS week ending 22 Dec 2018 : 1,546K(PS4 789K) week ending 29 Dec 2018 : 848K(PS4 502K), week ending 5 Jan 2019 : 449K(PS4 356K), week ending 12 Jan 2019 : 252K(PS4 221K); the trend of Switch is selling 55% , 53% , 56% the amount of the previous week in the above mentioned weeks, while PS4 64%, 71%, , 62%. Switch is slowing down like a rocket, more than PS4, as it has got the maximum boost from Dec, the "month of casual gamers". I'm more than sure that right now PS4 is on top worldwide, and it will be for many many weeks up to Nov 2019. It will be a bit down YOY ? It doesn't matter if PS4 will be slighty down YOY in 2019, it does matter that PS4 will make other 17M in 2019, keeping sales healthy and steady, after 6 years from release, which is a miracle if you ask me.
The holiday shopping season in general is "casual" season and the difference in Dec to Jan decline can be explained by 3 things.
1. Black Friday. In the US PS4 had the Spider Man bundle that was $100 under MSRP for a week and had no deals in December. On the other hand Switch had a decent Mario Kart bundle but it was only for 1 day and did not go under MSRP.
2. Games. The 2 biggest holiday games for PS4, Red Dead 2 & Black Ops 4, released in mid-late Oct. The 2 biggest holiday games for NSW, Pokemon & Smash, released in mid Nov-early Dec.
3. Japan. The holiday shopping season starts later in Japan and since this region makes up less than 10% of PS4 sales and close to 25% of Switch sales, of course Switch will benefit more.
These three things are what cause PS4 & NSW to have different Nov to Dec to Jan fluctuations, it has nothing to do with Dec being "casual month" and the fact you even came to that conclusion shows you really dont know how to look at and analyze data.
And no PS4 will not sell 17 million this year.