I don't think that you can put the offense's lack of production solely at the feet of Cavanaugh. Let's look at what he has to work with, or rather, what he doesn't have to work with.
QB: A second year starter who had but a handful of starts coming into the season. His true ability to play the game at this level was/is still unknown coming into this season. Not a good situation.
RB: Jamal Lewis and his legal problems hanging over the team this season certainly didn't help matters at all. Couple them losing him for his 2 game suspension with an injury to Musa Smith and Jamal's own injuries that cost him time and your vaunted running game isn't so vaunted anymore.
WR: Well, let's just start here by saying that there plain and simply is very little talent here. The talented duo of Johnson and Taylor didn't seem to strike much fear in the hearts of the opposition. Hymes played well at times this year but was sporadic at best. Big need here for the future. (Didn't they draft Darling this year as well?)
TE: A killer as your most talented receiving threat was lost for the vast majority of the season with an injury. No one stepped up here either or the void between first and second string must have been huge.
OL: Dinged up to say the least. How many games did All World tackle Ogden miss this year? The anchor of your line is in and out of the lineup a bunch this year, it's hard to get any continuity for the offense.
I just went over some of the highlights of the year that seemed to impede the Ravens. That's an awful big list for a talented offensive team to overcome and I wouldn't exactly classify the Ravens as that. It would seem to me that Cavanaugh really tried to salvage the best he could out a shambles. Heck, he even made Boller look like a legit pro when he had that one 4 TD game.
I think the bigger problem for the Ravens has been holding onto a player like Travis Taylor whom they seem to prideful to cut. Cut bait and move onto some who can help your team.
I like simple pleasures, like butter in my ass, lollipops in my mouth. That's just me.