The Minx line seemed hampered from the beginning by the fact that all the books were, with maybe one or two lonely exceptions, more in line with a vague idea of what tweenage girls should want to read than what they actually do read. They all seemed steeped in understatement, whimsy and / or boho culture on some level - with witty, misunderstood underdog heroines trying to make their way in a world they never made. All of which sounds great if you're a nostalgic late-thirty-something thinking about the kind of books you'd feel comfortable giving to your own junior-high-aged daughter.
But in reality, girls are just like boys who are just like everyone else: they like to be entertained, primarily, and the Minx books seemed to be saturated with a Grape Nuts brand counter-cultural conservatism of the type that ensures bland, generally well-meaning product will always win the day over any kind of energy or enthusiasm. There's no shame in pandering to kids: it's what kids entertainment is all about, really, because kids - even the supposedly older audience the Minx line was aimed at - are primed to accept pandering as their primary means of judging aesthetic worth. Kids and tweens don't give a good god damn whether or not something is "good" - I know I didn't even begin to form any kind of reliable sense of "taste" until I was old enough to seriously regret the crap I'd filled my mind with for the previous decade and change (it takes some people a lot longer). The Minx line didn't have any books that wanted to pander to their audience.
If you are a literate tweenage girl in today's world, your reading life probably revolves around one of two phenomenas: Gossip Girls or Twilight. One of them is a trashy, exploitative look at the vacuous lives of insanely overprivileged rich brats, the other is a trashy, exploitative look at teenage vampires who act out intensely felt, generously insipid emotions and get it on like rabbits. Notice the key elements - "trashy, exploitative". Boys like stuff that makes them feel like they're getting one-up on their parents by doing something supposedly "bad" for them, is it so different to imagine girls might like to do the same thing? They'll either get around to The Bell Jar when they're older or they won't, but trying to sell "good", "heartfelt" comics to kids, any type of kids, is always an enterprise doomed to failure. Kids don't want Care Bears, they want Wolverine. Kids want trash. They have to read the "good" stuff in school - and God knows when I was that age there were few things I hated more than Judy Bloom and S.E. Hinton. Even good kids literature is wrapped in trashy wrappers these days. Kids manga, and manga aimed at teenagers, is primarily trash - some of it well-done trash, but trash nonetheless. (Hence the fact that many respectable critics actually hold the Gossip Girls books to be grade-A social satire, with the tacit assumption that a good-sized portion of the intended audience can suss actually out the distinction for themselves without having to be condescended to.) Figure out what the kids want and sell it to them, even if you have to hold your nose while you're doing it. Anything less and you're just throwing your money away on good intentions.
Who was Minx's audience? Well-intentioned parents stocking up on wholesome stocking stuffers? Or the kids who actually saved up their allowances to buy Breaking Dawn at midnight sales events all over the country?