No, I'm serious. I had stepchildren and I thought I loved them as my own, but then I had my own.
Now the stepchildren didn't live with me, and they have their own mother. They love me, and I love them, but they don't love me like they love their mother, and I don't love them like I love my own children.
If you don't have children, you just don't know, and it's not an insult, it's just the truth.
I don't doubt your sincerity for a moment. I know you honestly believe what you're saying. I know you love your step-kids, but you love your own more. As my wife says, "there's a reason the first time every 350 lb. football player get his face on TV the first words out of his mouth are a diffident 'hi Mom.'"
Nevertheless, the world is full of "enabler" parents that "can't turn their back on their children." It makes very little difference to me what the "drug of choice" is; booze, dope, sex, it's all a variation on the same theme. They are all corrosive to the "life worth living," and sometimes require a "time out" for the child (even grown) to appreciate just how much it is costing to live that way.
Love is not fulfilling ones own desire for the presence of ones children. Love is caring more for them than for yourself, even to the point of denying yourself their affection if the circumstances are desperate enough to warrent it.
And it isn't any easier when there are other "parents" out there further enabling the wayward by telling them what bastards you are for not accepting their "choices."
I won't tell you about my children because that story isn't done yet, but I can tell you about myself, and trust me when I tell you my life has been immeasurably damaged because from a very early age I possessed enough verbal dexterity to mitigate damn near any sanction my parent brought to bear on me.
It was only when I went to live with the other parent (and their what I regard to be profound wisdom) that I learned just how badly I was injuring myself.