Yes. They've promoted it regularly for at least another year, and kept supporting the game until earlier in June, when the last Party Crash took place. Hell, it even got one more update made because it actually sold a bit higher than their expectations. If it didn't meet their expectations, then why would they continue to support it for 2 years?
Yes it was. The whole reason the game was made for the Switch in the first place was because the developers thought the Joy-Con were a natural fit for the punching mechanics of the game. Adding button controls was Yabuki's idea as he felt that a fighting game like this should allow players different options, and the Switch embraces such versatility. He even said that nearly half as many people play with Motion Controls as Button players. Small YouTube sample sizes don't compare to the actual stats the developers have access to.
There may have been an attempt to make it a viable competitive game. But that wasn't the main point of the game. It's primary function was to demonstrate the Joy-Con's use in a new kind of fighting game with a New IP. In that sense, it did fine. Sure, the competitive aspect may not have caught on the way they wanted, but that should not be a reason to give up. If anything, that should be a reason to improve. Fixing the problems of the original, while still keeping what they original did well is how you make a more successful sequel.
Unless you know what Nintendo's sales expectations were, there's no way to be certain. Do you really think ARMS had that kind of money put into it? It mostly likely didn't cost that much to make, and its marketing campaign was much smaller than the original Splatoon's, which was hyped to hell and back with events and endless commercials. ARMS had much more modest marketing with the occasional tournament, and standard commercials. Nintendo knew this probably wasn't going to be the next Splatoon, so it needed to bring in its own appeal.
Nintendo may not be as big as Sony or Microsoft, but they're not an indie studio. They've got 900 internal developers in their Kyoto and Tokyo Offices, and a multi-billion dollar net worth. Don't give me that "They don't have the resources" crap. ARMS did fine, selling solid, but not amazing numbers. Nintendo continued to Market and support the game for another year or two. Even the producer is interested in making a sequel. Nintendo's made sequels to games that sold far less than ARMS before. Pikmin and Rhythm Heaven being major examples.
1. You’re stretching by trying to equate an online feature being active for 2 years before stopping to be 2 years of support. The last real dev support ended in January 2018. An initial marketing push is not a result of success, it is an attempt at it.
2. If the goal was to show off the joy cons’ motion controls, as you say, then they failed for the reasons I already stated. When success looks like in that regard are the 20M+ selling motion games on Wii and driving the sales of tens of millions of consoles, a follow up selling a mere 2.1M and not creating any kind of significant sales wave can’t be regarded as successful.
3. Despite what you may think about Nintendo, their resources are not boundless when we’re talking about the devs that work on their core strategic titles. If it were a matter of spending some of the billions of dollars Nintendo has to push out some extra game, they wouldn’t have used their core devs. They would have used one of their lesser teams, bought a new team, or contracted a third party. Instead, they used the devs that made Wii-series and Mario Kart: games that have sold between 20 and 80 million+ and have been core to driving millions to tens of millions of console sales. These employees are a finite and extraordinarily valuable resource, not devs they use to push out titles with the expectation to only sell a couple million.
Nintendo made no strategic gains: no millions of extra consoles sold, no new markets created, no new massive 10M+ franchise established. If none of these things were a goal for Nintendo with this title, they’d not have used these particular resources for it. Especially in the launch period of one of their important consoles.
I describe myself as a little dose of toxic masculinity.