Cote I think I've seen you vigorously defending McEwan before, and I'm all for a discussion, but your tone seems unnecessarily combative here!
15 year old Lola (whose name I think is at the very least an unconscious echo of 'Lolita') is introduced as both precocious and vain: 'perfectly composed, having liberally applied perfume and changed into a green gingham frock to offset her colouring', with 'toenails painted vermilion': she's manipulative, 'pressing home her advantage' by invoking her parents' separation because she wants to play Arabella. Her 'nearly adult mind' is also mentioned, and when Paul meets her he sees that 'the girl was almost a young woman, poised and imperious, quite the little Pre-Raphaelite with her bangles and tresses, her painted nails and velvet choker.'
All of this, to me, seems like victim blaming ('and what kind of underwear were you wearing on the night of this alleged attack?').
Why does McEwan (and yes, I know ultimately it turns out this is Briony, but even more ultimately, it is he, and he does not give any sense that this particular aspect of the novel is merely B's perception) so carefully characterize the victim in this way? The suggestion is that Some Women (or rather, girls) will happily lie about rape, as she goes along with the popular mood against Robbie and scapegoats him ('false accusations ruin men's lives' agree the menz!), and it turns out that the attack which so upset her didn't stop her eventually marrying the man who did it ('they like it really!').
The entire novel is about the damage that a malicious accusation of rape can incur, and all our sympathies are directed toward the falsely accused Robbie - only very briefly to Lola, whom the text does rather seem to insist brought it on herself. Now, a false accusation of rape obviously is a terrible thing, but in this case a rape did happen, yet that is not the tragic event of the narrative.
I'm not asking that McEwan write about different things or write different books to dramatize the plights I personally feel are more deserving, but the extent to which I find this book problematic is based around those elements which I've tried to explain.