I think that's the thing that's clouding some people. Not to say they're wrong, but here's some perspective. We are most likely comparing the final version of the first game to the initial version of the second game. As I said before, the first game didn't even have the ranked modes, private battles, the slosher, the ink brush, the splattling, Mahi Mahi, etc. at launch. At least in the second game, all of them are available (ranked modes after level 10) at launch along with a new Salmon Run, new single player with ability to use multiple weapons, LAN play, new fixes to the multiplayer, and we just got the splat brella with more to come like the pirate ship stage.

Whether you care about that perspective, that's up to you. Nevertheless, that's how the development of Splatoon 1 came about post-launch.

Yeah, it's absurd that they removed the split-screen mode!

Wait, what?

Would it have been better if Nintendo instead came out with "Splatoon 1 Deluxe" for the Switch?

No, but it would have been better if Nintendo took an extra year to add more content to the sequel and craft it into something really special. Especially because it's a $60, marquee game that has a lot riding on it.

It depends, but considering this is the launch year of the Switch and Nintendo really needed to get the ball rolling quickly and throughout the year, Splatoon was definitely needed as a marquee title for this year. Otherwise, after ARMS, you would have to wait another month for the next big game for the Switch and Nintendo probably wanted momentum to keep going until Odyssey hits. As much as Mario has high popularity and could carry the mashup game with the Rabbids in September, Splatoon is the new hot commodity for Nintendo. Plus, they are making updates for a year akin to the first Splatoon so we'll see how much more content they could've added if it was delayed to next year.