I agree with Phantom that people should complain and rant about this - from an end-user point of view, having this sort of problems, regardless of when they are (at launch or not) is bad.
I wonder though what the alternatives are from the point of view for gaming companies. I was in on the early launch of the GW2 (having pre-ordered to play in the beta weekends, but that's a different story). There were indeed issues with the login servers being pretty badly overrun with a ton of players. Now, ANet had their pre-order numbers for that, and it's certainly plausible that they could have made a worse-case scenario that was much worse than the actual events that day (meaning, they could've anticipated 10x the amount of traffic on login servers), and its somewhat plausible that they could have prepared for it.
I thought about this on the launch day - but then it occurred to me - setting up redundant servers and anticipating worse-case scenarios is expensive. These extra servers and the setup would probably only be useful for launch day, after which the amount of traffic would die down (as it has) and the extra server setup would become unnecessary and probably only cost even more to maintain.
I'm not saying that companies don't want to have flawless launch days, but there's a cost associated with everything, so in my eyes, there's got to be some cost-benefit analysis that probably results in the fact that some launch day problems are a better alternative than over-preparing, in terms of cost. After all, the launch day problems can be handled, usually fairly quickly, by allocating exactly as many resources as are seen to be needed at that time, and the people who have issues will often times still go back and play the game, regardless of the issues (like I have: I had to wait 2hrs to login at one point, and while annoying, i still went back to play the next day and so on)
Anyway, I'm not an expert on this stuff, but that's my two cents.
Edit: Also, more on topic, making the single player portion of a game require constant internet connection is something that's absolutely bloody absurd in my mind, and something I'll never understand. I've yet to buy any game that required that sort of setup, and I never will. It pisses me off, especially because I often travel and won't always have a reliable internet connection. Yes, I know the arguments for piracy, and maybe it really benefits companies - but I still have my right to not buy a game based on that.