Impressive is a relative term here, I'd asume considering the hype and Nintendo's prognostics/predictions it was less impressive than most ppl expected/hoped it to be. I also think the Switch will have kind of an enormous hurdle to overcome when PS5 and the net XBox hit the market, so maybe it actualy needs to be more impressive than its being so far if it wants to have enought staying power to compete in equal footing with the next generation when it launches.

Regardless of relativity, 17 million is a great result for any system is a single year and I dont buy that excuse because it's also doing alot better than many people predicted.

As for PS5/XB4 affecting Switch sales, that's not going to happen. A user on this site, @Shadow1980, has data that shows that no console has every had any notable affect from the release of the successor to a competitor.

Genesis had no affect on NES, PS1 had no affect on SNES, 360 had no affect on PS2, 3DS had no affect on PSP, Wii U had no affect on PS3/360, Switch had no affect on PS4/XBO.

Funny how quick these things change, just a while ago a lot of people were certain the Switch was going to fail and now selling on par with the PS4 is unimpressive. The rest of your post doesn't make sense: The PS5 and Nextbox come after the Switch so they have a hurdle to overcome. Did the PS2 selling well help the Gamecube and Xbox? When has it ever been a good thing to compete against a sales juggernaut with your latest console?

If I remember correctly then 2015 was the PS4s peak year in the US, so being able to keep up with the best year of the PS4 is no small feat

I think the switch Numbers are ok. Because when you compare with the 3ds+wi u its almost the same, but if we compare with the Wii era....well. the same goes for PS4 with the PS3 and the PS2 era.

Comparing anything to the Wii era is setting up for failure, Nintendo sold over 250 million units of hardware between Wii & DS, that is a feat that had never been remotely close to happening before that and will never happen again.

NES+Game & Watch, SNES+Gameboy, N64+GB Color, Gamecube+GBA, Wii U+3DS each did 85-115 million and Switch is on pace to do similar numbers.

PS4 didn't have system sellers in 2015 on the level of Pokemon + Smash. Yet alone a system seller breaking software records like Smash. We have historical precedent of a console (X360) outselling another console (PS3) entire year with just November + December sales. It's not impossible.

PS4 also isn't a hybrid, drawing sales from two demographics, and has direct competition in the home console space with the XOne and to an extent PC's. On top of all of that, it had the higher price (even with temporary discounts). However, this can also be accredited to Nintendo for taking a risk and succeeding. 

Nintendo predicted 20 FY. Many Nintendo fans on this site expected 2 Million+ NPD for December. 

Obviously great Switch numbers. It just isn't outselling the PS4 launch aligned. Which speaks to what a beast the PS4 is!

guys just ignore the people talking nonsense better to ignore than thread going on pages of arguing nonsense

The ps4 had system sellers in almost every single month in 2015. I consider 2015 to be the first truly great year for the ps4 in terms of software. 

The switch is currently ahead of the ps4 launch aligned. Worldwide there is a gap of over 3 million in favour of the switch currently. This will of course shrink once ps4 hits it's holiday while the switch goes into the quietest time of the year. But still the switch is at the very least performing on par with the ps4 launch aligned.

Switch might outsell Wii lifetime sales by a good margin with good revisions and a price drop. There is no guarantee on how Nintendo will handle it's decisions though.