I agree w/ number 1 and 2 for BS, but #3 doesn't make much sense. If you pay attention to the movie the events arent' random at all. Small details clue you in into what he does and why.
And personally I like I,Robot better. I thought it had a good mix of humor, sci fi, and action. Many people complained about I,Robot's blatant use of advertising (Audi, FedEx, converse, Dos Equis, Etc) but I just tuned it out in favor of paying attention to the story rather than getting hung up on the details.
And as for why BS got a better rating...well, thats all based on why critics feel the way they do. That varies from person to person.