We can't say what is in her mind that is the thing, we don't know if she wants to quit, or maybe she feels she can't, or that she doesn't want to.
The person you knew going to AA, when he went to those meetings each time, was he going for himself, for someone else or cause he was told (ie judge) to go. If he didn't really want to quit, wasn't going for someone else and wasn't told to go, then everytime he went to the meeting he lied to himself, and others (family, friends, and others in the meetings) which is sad.
As to Lindsay, again we don't know and if she does then like a kid learning to walk, she will fall many times before she can stand on her own and then its the time factor minute, hour, day. If she doesn't want to stop, she will either die from the addiction or get to the point that her career will be a backseat deal low rated types and trying (as we heard about many stars) to do anything to score her next hit. But if she is trying to figure out herself and this addiction there is nothing anyone can say or do.
As to those who are considered enablers, how are they responsible. Lindsay willingly drank, she willingly took the drugs, some prescriptions she was on should have been monitored more closely (but again going only by what is reported, we don't know she wasn't) if she was then as we know in the world of Celebs you want something like that go to another doc, use another name... Was the prescripts a mis-diagnosis? That can happen, they brush her hyperness off as ADHD and throw her on some pills, but then for a long time that was the fenom if you will when it came to kids like that. As to the illegal substances, she willingly took it.
You could say but if she wasn't offered it... It doesn't matter she could have turned it down, she could have said no thanks. She didn't. Thing is maybe someone didn't offer it to her, maybe she went looking for it, to medicate herself from underlying problems, or to suppliment her other prescribed meds as they weren't doing enough (which means if she was monitored then they refused to raise the dose meaning she ran into docs that actually had ethics, wierd I know) in her opinion. But it all came down to her and her choices. And why she made the ones she did.
Like many stars confronting the demons (sometimes from in and outside the "celeb" status) is very difficult, many manage to do it, and many feel they need to self medicate. If or until Lindsay does this she has a long road ahead, and if she truely wants to stop she has to want to. She says she does and right now that is all we have to go on. Part of the problem is the fact that the public perception is like that with many child stars, who go out and party, they will either kill themselves or they shouldn't be in the business. But there are plenty who haven't gone the route she did, and others who have cleaned up their ways and committed to trying to stay clean.
They will slip, and they will pick themselves up, but before all that they had to want to, they had to find the strength and they had to face and/or fight the reason they started. And do this every single day for the rest of their lives.