Scales. Scales is my pet peeve.
In order to get them, you have to kill a King Salmonid. It usually takes me 3 or 4 shifts before I can get one to show up, and 4 or 5 is usually how many shifts I play during a Salmon Run session before I get tired and want to do something else, so I don't get scales too frequently, but that's not bad in and of itself.
Then there's the drop rates, and this is where I start to have more issues. I don't think I'm alone in saying that it's a little goofy how low they can be. They also lead to the reward not really matching if our crew succeeded or not. I've gotten gold and silver scales while only getting a King to about half health, but all Bronze when beating a King with more than 30 seconds left. IMO, A successful kill should guarantee a certain amount of silver and gold scales depending on Hazard Level.
The shop is where I have less of a critical problem and more of just a pissy nitpick, but I'll get into nonetheless . Most of the prices are reasonable for someone who plays Salmon Run frequently, and even if plenty of them can be ridiculous, all of the rewards for a while were strictly Salmon Run-themed, so only a big fan of the mode would be miffed about not having them in the first place. Of course, some of the prices in conjunction with the previous issues I've mentioned are just absolutely stupid no matter how I look at it. Then, they added the previous game's Salmon Run gear rewards to this game, and they put them in the stupid scale shop!!! I don't know how else they would integrate them besides letting them be random drops from gear capsules, which would also suck, so I guess this is the lesser of two evils. Still though, why am I paying 300 bronze for the got dang Headlamp Helmet. The S1 Octoling Goggles in particular greatly upset me because that's my favorite piece of gear ever, but I gotta do the dumb scales grind to get it.
This turned into more than a pet peeve should warrant, so I guess my other pet peeve is that the Rise of the Mammalians octoling gear isn't something I can wear. Let me slay, Nintendo. Stop holding me back.