As a Wii U owner, no. It's not. And it's just a lazy way to make the year look better for the system than it is. I mean we got, what? Mario Kart, Pokken, Rayman Legends, Lego City Undercover, DQX (Japan), and I'm sure much much more.
Jesus, imagine if this had been a regular Nintendo console with BC. This year wouldn't be much better than previous years! With the only (major) exclusive being Mario. Which is cool, but currently it's "must buy" is a game originally intended as a Wii U exclusive. Which is, in my opinion, extremely pathetic.
1-2 Switch, Snipperclips, ARMS, Splatoon 2, Mario Rabbids, Fire Emblem Warriors, Xenoblade 2 and Mario Odyssey, so there is plenty good Nintendo games in first 10 months of Switch even for Wii U owners. Only Nintendo Wii U ports are MK8D and Pokken Tournament DX, while Zelda BotW is brand new game with dual release.
It's a portable console, you can take all these games with you on the go... That wouldn't be possible on a backwards compatible console... Optical disk media and portable gaming are not a match made in heaven. Too easy to get damaged and the disk drive would take up too much space making the console too bulky to take on the go and leaves less room for components that make the Switch as powerful as it is (for a portable console).
And Mario Kart 8 Deluxe is a greatly enhanced port with 5 new battle modes and actual battle stages, all the DLC included for free, new characters and running at 1080p 60fps.
The Wii was also backwards compatible with the Gamecube, but it still got a launch port of Twilight Princess and it definitely helped sell a lot of consoles in the first few months. Breath of the Wild on the Switch got released on the same time as the Wii U version anyway, so it's a brand new game and not "just a port" as you make it out to be. It's also superior to the Wii U game and it looks A LOT better in handheld mode than on a big screen TV. Runs smoother as well.
So no, the only major exclusive is not Mario...
It's The Legend of Zelda: Breath of the Wild, Mario Kart 8 Deluxe, Arms, Splatoon 2, Mario + Rabbids: Kingdom Battle, Pokkén Tournament DX (adds five new characters), Super Mario Odyssey and Xenoblade Chronicles 2.
Also, the Switch only sold 13 million consoles during its entire lifetime, which means a lot of people didn't get to enjoy these great Wii U games. It would be stupid of Nintendo to not make ports of some of these games.
It's not like these remasters take away resources that would've gone to brand new games instead...
Pokkén Tournament DX is developed by Bandai Namco and the extra content comes from the Arcade version anyway...
Mario Kart 8 Deluxe was developed by the Mario Kart team and they recently released a brand new IP as well... But for some reason you seem to ignore Arms.
The Legend of Zelda: Breath of the Wild port to the Switch probably delayed the game, but it was well worth it. Hard to argue against sales numbers and critical reception. They're also releasing a story expansion this holiday season...
Lego City Undercover was developed by a third party studio and it got ports for all current-gen consoles, so it would make no sense to leave the Switch out. It probably sold better on the Switch than the PS4 anyway. And Switch will get all the brand new Lego games anyway, like Lego Worlds...
Rayman Definitive Version is being developed by Ubisoft and it's not like Ubisoft is not supporting the Switch with brand new games... So far they've announced Starlink: Battle for Atlus, Steep, Just Dance 2017 & 2018 and Mario + Luigi: Battle Kingdom.
Dragon Quest X is developed by Square and so far Square has been one of the best supporters of the Nintendo Switch with games like Dragon Quest Heroes 1 & II, Dragon Quest XI, Project Octopath Traveler, I Am Setsuna, Lost Sphear, etc.
It's a shit handheld. Battery life is absolute garbage. That on top of it being a weak console and you got yourself a system that can do a lot but nothing particularly well. Im a handheld enthusiast. But I cannot recommend something that can barely go further than the Wii U gamepad without a charge. 3-4hrs is fucking sad. The Switch is a decent idea but poorly executed. It'll continue to be a fucking pathetic excuse of a handheld until it can last at least 8hrs without a charge. As for the console part, there are better options. I have my PS4 and PC for games on my TV. I'd only use it as a handheld. But since it fails at even that, it really has no use until they fix the battery. And no, I won't buy a 3rd party battery to make it work the way it was intended.
Switch battery life is similar to launch 3DS battery life. You can't expect much battery life for 6.2" that plays full home console games, at least 8 hrs battery life is not realistic at all today, last few handhelds have better life max of 5 hours. Maybe we could have up to 5 hrs battery with Switch Mini/Pocket that could be used just in handheld mode, but hardly above 5hrs. Also comparing Wii U gamepad and Switch doesn't make sense, Wii U gamepad was just streaming device, while Switch has hole hardware (CPU, GPU, RAM...).
It really depends in the reasoning behind it but we won't ever know. If nintendo is doing that to fill in gaps in it's game release schedule then no. If it's using resources that could have went into new IPs or more releases of their established series then no. If nintendo is doing it to so people who didn't play them on the wii u can play them now and they're making more money while at it, then yes.
Reasoning is very obvious, Wii U is biggest Nintendo fail with terrible sales but had some great games, so most of future Switch owners didnt played them, also Switch offers full handheld mode compared to Wii U, so totally make sense to port some good Wii U games (even some 3rd party games), its easy profit for Nintendo, while plenty of people who didn't had those games will be able to play them, some Wii U owners will do doulbe dip beacuse of full handheld mode, and Switch lineup of games will be stronger and more diverse in any case.
Ports are cheap and they can be done in months, so it's not like Nintendo could do new game or new IP for same time and resources they are spending on porting. And its not about Nintendo only, Sony and lots 3rd party doing same thing, even PS4 that dont have full handheld mode and where on PS3 much more people were able to play some of great Sony games than people were on Wii U. Sony ported TLoU, Uncharted 1, Uncharted 2, Uncharted 3, GoW 3, Journey, Heavy Rain, Beyond: Two Souls...