Save scumming for equipment is actually a good thing.
For a game to be competitive, there needs to be an even playing field for as many players as possible. This means that everyone should have as much access to the exact gear they want as possible. If a majority of people save scum, more people are going to have easier access to optimal gear and the playing field will be more even. It doesn't matter what the game or the developers say, an even playing field is an even playing field. Period.
It's the same as, say, genning difficult-to-get Pokemon for competition. RNG, rarity, event-exclusivity, etc should never prevent specific people from being able to use the tools they want within the normal bounds of the game. People DO get off-brand perfect rolls without save scumming. SS-S LSDJ has 3 special charges on Ink Resist shoes, Pikachu.SF has a Ninja Squid shirt with 3 Swim Speeds, etc, and they don't save scum. Those are good examples of RNG being unfair.
It does suck that players with digital copies of the game have a harder time save scumming, but there are still things you can do:
Digital players CAN still save scum, but they really should horde a ton of resources before doing so (I'd say at least two million), especially when going for low-chance rolls, to mitigate the longer backup and restore process.
Players can, of course, order off of their clanmates and common opponents, although you'll usually end up with two slots copied at best instead of 3. (
I suspect that save scumming a file with perfect gear in town to order every day will result in different results every time, but I don't know this for sure. I do know for a fact that your gear's subs are determined at or before the moment you order from Spyke, so scumming a file that has gear ready for pickup does nothing.)
The most important way to increase your chances of getting gear is actually to not go for perfect off-brand rolls. Spreading your subs over multiple pieces of gear increases your chances dramatically (although they are still not very high, you go from ~1 in 4500 to ~1 in 600 depending on what you're trying to do). It is still best to horde money and save scum with digital to achieve this, but know that you can manipulate RNG slightly in your favor by spreading your subs around. it makes your perfect build more possible, although it also makes it hard to use the same pieces of gear in multiple builds.
I have a save scumming and RNG manipulation guide written here.
Then there are of course, people who do absolutely
nothing to increase their chances of getting good gear and try to call out those who did the smart thing. Those people don't have the right to call anyone out and we can ignore them. It's like a kid who didn't study for an exam and failed, then talked trash on kids who got good grades. Shut up, kid.
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Save scumming for rank is an entirely different issue. On one hand, low level players scumming for high ranks is bad for matchmaking because it screws with Solo Queue's team balancing, and it's honestly pretty pathetic. People who scum and act like they didn't is also pathetic.
On the other hand, there are plenty of S players on high-level teams that just don't play or enjoy Solo Queue, and I don't see anything wrong with them scumming to get S+, never touching Solo Queue again, and being honest about scumming when asked about it. Performance as an individual in Solo Queue is
quite certainly irrelevant compared to the performance of a team in Team Queue, Tournaments, Competitive Customs, etc. It's
always been that way throughout the history of online team shooters and Splatoon is no different. Since the ranking system doesn't reward the best teams in the game for being the best teams, those high-level teams can go ahead and use an exploit to get the S+'s they should have already gotten for winning so much. There's nothing wrong with them getting the extra 1K per win, and it's better for the game if the best teams search Team Queue with the highest rank and therefore have less chances of pub stomping low-level players.
The problem is, of course, that it's all an honor system. People have to say "I am on one of the best teams and deserve S+" and actually deserve S+. It's just such a problem that a collective team is judged by a rank that is not related to their collective team, so what else are you going to do? Some people will do it and it will be okay, but others will do it and it won't be okay. Some people will be honest about it, others won't. There's simply no way to enforce things. It would be nice if S players could move up and down S and S+ but not lose S, but that doesn't happen so we are stuck with what we're stuck with.
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In the end, save scumming is a good thing as far as equipment is concerned, and is a cloudy issue as far as rank is concerned.