This sounds more like political manoeuvring to me. If they've got the game running on the PS3 then there is no reason that the DLC wouldn't 'work' it's just a patch.
Their dev teams can't code themselves out of a paper bag. I'm not at all surprised that the PS3 is giving them serious troubles, given how it requires concurrent software to use all of the hardware (8 smaller cores over the Xbox's 3 larger ones, iirc).
Given the complexity of the world simulations they are building and that they basically are successful at creating, I don't think I'd use such strong language. It takes a lot of talent and hard work to ship something like Skyrim.
Bug ridden technical nightmare? I don't think I'd go that far either. Skyrim was very playable on the Xbox 360. Not too many bugs that I noticed, but I'm sure they are there if you look for them.
On top of that Bethesda is one of the few companies that still create games with very high replay value, there are not many (i currently cant come up with even one) who still create games "with endings" (i.e. not MMO/RTS type games) where you can put in that many hours and still be entertained.
If you actually hate bethesdas creations, I simply think you hate the type of games, not the product itself.
They are one of the few development studios capable of making large open-world games that are fun to play, and they make it fairly easy for PC gamers to mod the game as well.
I'll take buggy Skyrim over no Skyrim. Same goes for a game like Dark Souls. Not the most stable game ever made, but probably the best action RPG ever made and one of the best overall games.
If they are so bad at game development, surely it should be easier for another group of developers to beat them at their own game?
While these issues where patched later, its not surprising that the Dawnguard DLC which includes new animations that stress the XBox and low end PCs, when combined with existing PS3 issues would mean they can't get tit to work.
http://venturebeat.com/2011/12/06/fixing-skyrim-would-take-a...
Still, this is not a new problem - Las Vegas had it, Skyrim has it again. Its not like it hit them suddenly. I imagine that Dawnguard basically goes over the top in that regard. Still, it seems like they chose an implementation of a specific problem that does not address the specifics of a major target platform, which sucks.
One of the best mods I have installed for New Vegas is CASM, which saves the game every 10 minutes with a rotating number of autosaves. Very helpful if the save file jumps from 500k to 10mb.