We paid for the game because we took a risk with our money and trusted Nintendo that NH would deliver the AC experience we wanted. I don't think we necessarily paid for the "right" to tell Nintendo how to run their game when we already paid the full amount for it. However, they can lose our business on future products, and that's probably their motive for giving us a good experience in NH/listening to us. But I suspect they don't have to listen to their players/agree with them on every single thing to keep them hooked - if Nintendo already owns your wallet, you can't really vote with it.
Anyway, I'm one of those wild people who has never run out of storage on a 16 GB phone. That's how the storage/design slot thing in this game feels to me - it makes me wonder if a lot of people just have a hoarding mentality when it comes to some stuff, or can't be bothered to clean out stuff they don't use? It's one thing if you use every single design slot somewhere on your island and you absolutely cannot complete your dream island without compromising something, or you're running a cataloguing service, but after I hit like 700 or so things it's time to clean out my closet and clothes I probably won't wear again. Just like on a phone, I clean out apps I haven't used in a minute.
But then again I always operate on the assumption nothing will change and I should always learn to work within the limits I have. I'm not the type to demand something change for my own comfort - especially something so insignificant as a first-world recreational luxury good (read: video game).
I realize a lot of people don't think like I do. Maybe that's the difference between the op's opinion and that of others?