It's nice if someone's subjective experience of being published makes them happy -- but sales numbers in the teens, or in the hundreds of copies sold over a period of years, is not what normally gets called success.
I don't have a problem with an individual saying that they feel they've had a successful personal experience. That's something only they can know. But it's a subjective internal experience. It's not successful publishing.
I've known Old Hack on AW for years now. If she calls a publishing operation "unscrupulous" or "exploitive", I take her seriously. But for those who are bothered by such words, I have some alternate or additional adjectives:
Incompetent. You don't have to prove evil intent to observe that a person or organization isn't very good at what they're doing.
Someone else's hobby. There's little risk in someone setting up as a publisher if, when they undertake to publish a book, they hazard so little of their own money that the failure of an individual title to sell in any significant numbers is merely regrettable, rather than a personally painful financial loss.
Meanwhile, every writer who licenses a book to a publisher, and everyone who does editorial or production work for them, is putting up a big chunk of their time, their effort, and in some cases their original ideas. If they understand that what they're doing is a hobby, and don't count the cost to themselves, that's not a problem. Trouble comes when they think that what they're doing is supposed to be paying work.
Unfair. It's not all that difficult to run a publishing operation that randomly or semi-randomly fails to do right by many of its books, but sometimes does a relatively competent job on others.
If a book is lucky; if it's well-timed; if it's a straightforward and congenial piece of work for its pre-press Virgils; if it raises no troublesome packaging or marketing or production issues; in short if it is in all ways convenient, it's going to take about one-twentieth as much effort to publish as its more awkward brethren. Much of that work can be handled by intelligent amateurs who don't have to account for the amount of time they spend doing it.
But as anyone who's worked in commercial publishing can tell you, books that are naturally easy to publish are rare, and you can't predict which ones they'll be. Moreover, an author who writes such a blessed book may find that their next title, which superficially doesn't look all that different, is cross-grained and unlucky at every step of the way. At that point, they need to have it being worked on by experienced pros who've seen and wrestled with a wide range of problems, and who cover their rent by dealing with those problems in a prompt and professional fashion.
It's unfair to organize a company in ways that make things easy on yourself, if that structure imposes an unpredictable and potentially large amount of risk on others.
Low yield. This one's simple: much work, few readers, little pay. Your time and labor are your own, but you have to ask yourself whether you wouldn't be getting more for it elsewhere.