This topic is kinda cute. There are people here who refuse to believe previous generations of games had problems anywhere near as bad as this one.
Truth is, gamebreaking glitches existed in games prior to this gen. Even in the ones you love. Zelda games had unwinnable situations that players could get themselves into, despite a bit of difficulty towards getting there.
Someone here mentioned that they never saw a PS2 game have the same issues as AC:U? Well let me tell you about the Deus Ex port. What a shitstorm that was.
Basically, you had to reformat your card to save the data. You can say no and work around it somehow, but if you did that, the card would magically reformat itself randomly. So all that hardwork from other games you had saved?
Fucking gone.
And let's just say you have a brand new memory card. It's clean, you formatted it (you'll know because the game does this for you, how kind!), and you are playing some Deus Ex. Uh oh, looks like it just randomly decided to reformat again. Why? Because fuck you.
Soul Calibur 3 would just randomly corrupt itself too. Man that was fun. All that time spent adventuring, all my custom characters, poof! Gone!
We were kids back then. It pissed us off, and maybe some of us went to the forums to complain. But the internet wasn't as big, so the problems weren't as widespread, despite being just as bad.
If anything, things have gotten better. AC:U and other games are outliers compared to how many titles come out with no problems, but it's another side of the spectrum - too heavy of a reliance on patches in general.
But yeah, believing the previous generations to be untouchable is bullshit and pure nostalgia. It's not an AAA game by any means, but Action 52 was a thing, and if you don't know about that game, it's probably one of the most broken, shitty games to ever exist.
You can't even beat some of the 52 games, as doing so would either crash the cart or just end up sending you back to the previous menu. That sort of quality, when taking everything into account, was far more common in the yesteryears.
Huh weird looks like my post didn't make it when I submitted yesterday.
But basically if it was discovered after being minted they would either reprint the game if it was popular enough with an update or not bother. You could call in to the company, send your game off, and get a new updated one back. This happened most recently with guitar hero 3 on the Wii which had a bug where it only played in mono sound and since Wii games couldn't be updated you had to send the disc to Activision and they fixed it up. Got some extra goodies too.
That happened sometimes. A few developers would be nice enough to do so, but most told me to fuck right off or return the game.