No offense, but the example you have described it completely the customer's fault. You are suggesting that people have prior difficulties with bethesda games, but turn a blind eye to their own experiences and repeat their mistakes. Sorry, but wanting to play a video game is not a justification for ignoring common sense and good consumer decision making.
If you genuinely believe that Bethesda struggles with the PS3 platform, as you have suggested them having a "history" of, then it is YOUR responsibility as a consumer to make an informed decision. Saying you are repeating a mistake because you hope someone else will solve the problem just makes you look negligent or incompetent. The problem may or may not be fixed, but every consumer is responsible for making their own informed purchasing decisions.
This sounds reasonable, but is unfortunately not accurate. By presenting their product as fully functional on the PS3, Bethesda enters into an agreement of implied warranty with the customer. Regardless of prior history, which cannot be assumed knowledge on the part of any or all consumers (which, in this case, is a moot point due to Bethesda's own, unprompted pre-release statement regarding Skyrim on PS3).
If their product does not work as described, they, and only they are liable.
There are plenty of brands and manufacturers with sordid pasts - but this does not allow them to engage in bait and switch or non-disclaimed "as-is" sales practices.
Your argument would be better served in defending Bethesda against attacks on the quality of the base game. In regards to DLC: you cannot simply say "well, we were gonna" and expect that to be okay. If you bought a computer with a, say, certain graphics card being advertised as coming pre-installed, but when the computer was delivered, the card was missing, would that be your fault? Let's say the computer company said "well, we didn't realize how incompatible these two items are, but we're working on it. No ETA, and it's not like you bought the CPU just for the card..." Your fault, too?
I just fail to understand how commenters - many of whom are obviously unaffected by this situation - continue to try to shift blame away from Bethesda - or turn this into some sort of greater, moral debate. The facts are plain and simple: each PS3 disc is currently defective, per it's described purpose. It is solely the responsibility of Bethesda to remedy this, or face the consequences - which extend beyond simply "losing customers." This is where the past examples also fail: at the very least, promised product features were delivered for prior games. Performance issues notwithstanding, to promise something and not deliver it - as a manufacturer - leaves you, and you alone, liable.