Hahaha. Well, I can understand that a lot of people won't like this anime for all the various reasons you've stated. The characters are stupid as hell and the story got more random.
Copy and paste (I was waiting for this thread to pop up!):
For some reason, I always have sympathy for the most ignored and pitiful characters, and this isn't an exception. Enter Kotonoha, a shy racked girl who is Makoto's first love interest but despite getting off to a nice and rusty start, she keeps calling off Makoto's lust and whithers away from his attention. It's sad to see her being ignored for most of the series, though her persistence and loyalty won me over. Each episode had her mentally taken apart until she almost becomes an empty shell. I heard she was meaner in the game (proven in the game ending where she takes the saw to the bridge), but here she's diluted to a shy stock girl - perfect for the ultimate yandere (wiki). Though she's not entirely diluted - the ending was still believable even after the ordeal she had to go through. Her NICE BOAT scene was very bittersweet, having withstood 10 episodes of emotional drainage. Thus Kotonoha wins me over as being my favourite character in School Days.