Did you even play any of the iconic RPG's prior to EA's involvement? Did you ever try to play Baldur's Gate 2 unmodded? It had a horrendous amount of bugs and glitches, many of them totally game-breaking, yet is still hailed as the best RPG ever. Star Wars: Knights of the Old Republic? Also had quite a number of bugs.
And that is the case with most large, complex video games. Hell, it's the cast with most types of software. You cannot possibly test a product enough to discover all bugs, even all critical bugs, especially in a game as complex as RPG's tend to be. Something that only occurs 1% of the time might be almost impossible to spot during development, but becomes very obvious when hundreds of thousands of people are playing. The more complex the software, the more options, the more variations that exist, the more bugs it will have because it is simply practically impossible to make bug-free software. Unless you're designing life-critical systems (power plants, medical equipment, etc) where failing is not an option, but I doubt you'd want to pay the price of a game with such a costly quality assurance.
No, release quality in video games has not declined. Old games had plenty of bugs. Games today tend to be larger and more varied, though, which will invariably result in more bugs. But look at games like Baldur's Gate 2 and see how many bugs they had.
Oh god yes, this. While I didn't have any problems that I can remember with SoA, I could not even play Throne of Bhaal until a patch came out. IIRC, it was an issue with some CD drives not properly reading the files or something. Oh, and I didn't even have internet at the time, so I had to get a friend to download the patch, copy it onto a blank CD and give it to me at school, before I could even start playing.
And even today, it's not just the big companies like EA and Ubisoft. Take Paradox Interactive - a relatively small developer/publisher (at least compared to EA, Ubisoft, etc) and probably my favourite current game developer, yet their games and even patches are often buggy nigh-unplayable messes on release. QC in the gaming industry as a whole is, and has long been, crap. There are some justifications for this, the sheer complexity of software and the variety of systems doesn't help. But regardless of the causes, it's nothing new, and it's not EA to blame (or at least, no more so than any other publisher or developer).