Wow, your take on it sounds a lot like IGN's review. I'll take you word for it, that's kind of what I expected. You have a good grasp of cinema so I hold your opinion in high regards...granted, I still have to watch it sooner or later.
"I am Legend" is one of my favorite books, probably in the top ten, but I guess the filmmakers of the last three adaptations didn't think a direct adaptation would be suitable for the masses. I've only seen "Omega Man", which was great but considerably different. "I am Legend" is a book that seems perfect for a direct adaptation, I don't understand why they need to change everything. Many stories benefit from changes in story and characters to better fit the format, but this is one that seems very suitable for absolute translation to film.
The book is a classic, inspiring not only the zombie sub-genre, (Romero's movies were inspired by the book), but many of the leading and prolific horror-fiction writers since, for example Stephen King. If nothing else I'm glad that Romero incorporated the political and philosophical undertones of the original books, (at least initially). I don't care if an adaptation sticks completely to the source material as long as they successfully get the feeling, atmosphere, and overall point across to the viewer.
Hopefully one day we will see a truly worthy adaptation of the book, until then, please read the book....anyone who hasn't already, please do. If for nothing else to better your understanding of the zombie sub-genre and all that it truly stands for. It's a fairly short story, not necessarily ground-breaking, but definitely worth the read.