Clearly you don't play on PS3. Certain areas are almost unplayable at any stage in the game (Bitter Springs, Red Rock Canyon, the Gomorrah) but even worse when your save files are larger.
And regardless of how much work Obsidian did, it's the publisher that makes the support decisions and Bethesda dropped the ball on this one. They announced they were "turning out the lights".
You can test all you want prior to releasing DLCs but you're not going to catch everything. Releasing three DLCs and pulling the plug with no final patch, especially when some issues, well known ones for the platform, were never addressed... well, shame on Bethesda.