All this is true, and I certainly don't think they can please everyone, but there are still things they can do.
A nice price point doesn't need people to come up with crazy theories or excuses. A strong launch line up won't lead to too much badmouthing (but I'm aware some people are never happy). Solid, modern OS features will be met with "Well, took you long enough" at worst and "Yes, finally!" from others.
Those enough wouldn't turn the tides in their public perception, but it's a start. Yes, there would still need to be a big, new feature that would get people talking but I'm sure Nintendo can do something with obvious, significant appeal. I just don't want another situation in 2018 where Nintendo says "Too bad we couldn't produce the software that convince people playing games with their tongues wasn't life changing. We'll work to make that happen in the future".