Its a very controversial subject. I got my message deleted by a mod because my opinion is not confirmed by "science" so it makes it hard to make a point here. My tone was perhaps wrong, and I apologize for that, but I don't think the mod is right about requiring speaking about the NS10s strictly within the "flat curve" science context. I know this is ASR, but you gotta have some understanding what things are designed for. The NS10s are appreciated precisely because they violate the "flat" scientific standard!
So I'll try just this one more time.
ASR/Erin tests speakers based on a set standard. Based on this standard yes, the NS10s are garbage. It's true and I'm fine with that. But this standard exists sort of in a vacuum context. Some tools are designed (on purpose or by accident) to break that standard and work with that standard turned inside out. Because that's what the job requires.
There's a good article here about why "ruler flat" is not sought for in the professional world.
Also, there's a reason why everyone sets their EQ curve to a smiley face. Because it's musical. Science tells them "you're doing it wrong", but science can take a hike when it comes to pleasure. I'll do what I enjoy, thank you, science.
The NS10s are being phased out of studios, you don't see them as often as 20-30 years ago, but they're still very common and very much in use by those who appreciate them. If fact, I personally do appreciate "the hate" because, well, that just makes extra spare pairs available for purchase if you happen to need them. There are less and less mint pairs available these days. I personally went thought a lot of "scientifically great" studio monitors but was never quite happy (including popular Neumanns) until I got the NS10s. Haven't looked at any other monitors since (but it does help that I have the Neumanns). The NS10s make my job so much easier. Much easier than the Neumanns.
A lot of professionals hate the NS10s too (and use other monitors for the same purpose), and it's ok. Professionals have strong opinions about all kinds of tools they use, amplifiers, mixing consoles, compressor, all kinds of stuff and most of it is interchangeable and there are other monitors that can do the NS10s job more or less. The NS10s have been a butt of jokes and a subject of hate for a long time and it's also ok, who cares really.
Bottom line though, to judge them
as a professional tool you must be a professional yourself and have a profound appreciation of what a tool bring to your work. As a music listener looking for a pair of nice hifi speakers, you will likely dislike their sound and your opinions are perfectly valid on their own and need no debate. There are tons of much more pleasant sounding speakers out there. When I say they sound "fine" or "good to me", it's just that. They don't sound fantastic by any stretch of imagination. But I personally use them as my desktop speakers instead of switching to much more pleasing sounding Neumanns 99% of the time and they never bother me.
So this discussion should probably be about people's experiences with mixing on them, not listening to them in the context of home audio. Mixing = love/hate, home audio = definitely hate.