Do you usually start games in the middle? The game is broken up into two parts, IN part because of file size. But it's all ONE story.
How many books do you just flip to the middle and read a summary of the first half of the book, rather than reading the whole book?
Another analogy: if you're watching a TV show that you've enjoyed from the beginning, would tell a friend a summary of the series and just tell them to start watching from the middle? Do you think they'd enjoy it as much as you have, even though they won't have as much investment in the characters you've grown to like/hate/etc.?
I can't say anything about your problem with the writing. To each their own, but I didn't have a huge problem with it. The story drew me in anyway.