When I read that I thought 'Wow, bit rough on Ginny'. Rowling didn't even mention her.
I loved the Harry/Ginny pairing. It made psychological sense. If Harry was going to end up with somebody other than Hermione, it would kinda have to be someone 'out of the blue', as there weren't that many well-developed female characters Harry's age. (Or, well, any aside from Hermione...) But because Ginny and Harry had been around each other a lot and spent a lot of time together, even if it was 'offscreen', it made sense for them to develop a liking and attraction. Even if you didn't actually see it happening organically, you could imagine it happening organically, which would have been harder if he'd randomly started going out with, say, Hannah Abbot or one of the Patel girls. You know? Plus, I was glad he ended up being truly part of the Weasley family. That was nice. :)
As for Ron and Hermione - I like the pairing OK, and I'm glad Harry and Hermione didn't end up together, but I can kind of see Rowling's point. What does Ron have going for him, exactly? He's not smart - and I don't just mean book smart, he doesn't show much intelligence of any kind. He's not particularly nice - he grumps and sulks through half the books, with a chip on his shoulder a foot long about being a) poor, b)the sixth child, c) not Harry. People say he's brave, which... I guess?... but not compared to Hermione and Harry. He's not particularly funny. He's not described as being good-looking. He's not talented at sports. He's not particularly talented at anything - wizard chess, maybe? He doesn't strike you as the type who's going to be rich and successful. He doesn't stand out as a devoted/caring/protective brother or son.
I mean, I like the character well enough. But he's not, per se, a catch. Whereas Hermione is incredibly smart and gifted, is described as good-looking in the later books, is very brave, resourceful, uncomplaining in difficult circumstances, and generally awesome. I can see why she likes him - driven people often end up with laid-back people - but that's a different question to 'is he good enough for her?' Technically, I don't think he is. Doesn't mean they wouldn't be happy; just means he got the better end of the deal.