Jay Cutler doesn't get good protection at all. The Bengals were easily getting pressure w/ their 4 man rush, and against the Falcons got pressure on a 3 man rush on the Bears final drive, which is pathetic. Orlando Pace has played adequately, but Robert Geathers was beating him almost every play. Frank Omiyale is a revolving door at LG who can't run block at all. Olin Kreutz has been awful this season, and is a huge reason why Jay has 7 fumbles on the year. Kreutz has also been getting dominating at the Point of Attack and Nose Tackles are just harassing him.
Chris Williams is playing out of position at RT and he's done alright. He's a poor run blocker, and you need your RT to be a nasty run-blocker w/ a mean streak. Chris doesn't have that. As for Roberto Garza, he's unfortunately the only player on the O-Line that's playing well, which is saying a lot.
The defense was just awful. Words can not describe how bad the run defense and coverage was. Carson was never touched and he picked apart Lovie's Cover 2 defense. It's abundantly clear that the Bears miss Brian Urlacher and Pisa. As for Jay, he hasn't played up to expectations. He's been making bad decisions and when he gets frustrated like he did against the Bengals, he will force throws that can or will get picked off. But without a running game, teams know that the Bears will be throwing most of the time. And lastly, why are people complaining about Forte's 6 carries? Are they supposed to run the ball when they're 31 points down?
You can call these "excuses", but facts are facts. I'm not saying that Jay has been playing as well as he should be, but you can't ignore the porous O-Line which is causing Jay and the running to suffer immensely.