Yup, a lot of the same knocks also apply to Cat food... by products, BHT/BHA, use of corn as a cheap ingredient, etc.
The worst offenders, in terms of image (premium) versus actual product quality (cheap trash) are Hill's (Colgate-Palmolive) and Eukanuba/Iams (Procter & Gamble). Hill's is the worst though, since they're the only "premium" food to even dare to use long-banned preservatives like BHT and BHA. Unfortunately because they work so hard to get in with the vet sector (free samples, lots of incentives to vets) to gain credibility by association, they have a very high, very premium brand image with the average uninformed person.
Unfortunately feeding your dog/cat the cheap bulk dog or kitty food from WalMart or Sam's Club will be just as good or better than Hill's considering Hill's ingredients are just as cheap (by-products, corn, and carcinogenic preservatives) if not cheaper.