Professional testers would be ideal, of course, I absolutely agree. But that seems so far away from reality at the moment that I haven't even seriously considered it.
If they have just a fraction of the team they claim to be working on ED, they do have professional testers. Any software developer of this size not having testers would be absolutely insane. That's even before mentioning that FD more than once spoke of internal testing. Which you usually don't let the developers do, but the testers. So the developers can continuing implementing new features and squishing bugs.
All in all, my impression is not that no testing happens. But that the developers were not given enough time to go through all the bug reports, be it from internal testing or from player feedback, to ever handle all the things going wrong. So while testing probably happens, somebody in management decided that there's no time for further bugfix cycles and rather decided to roll it out.
Mind you, the "product matures at the customers system" is not unheard of on other software. And not limited to games, either. As long as you understand the severity of the problems you still deliver and have a good connection to your customer, this method might even be a good way to go. (I know that from my own line of work. We generally have a contract to deliver zero cathegory 1 issues, a limited number of cathegory 2 issues and a rather high margain of cathegory 3 issues. Cat2 will then be fixed within a few months, while Cat3 has to be fixed at the next major update. )
Unfortunately somebody here did not understand the limits. They pushed a software on us, which clearly had a number of Cat1 issuses still. With the outcome we all know. And the sad thing is: would they just have taken one more month, and have delivered it in the state we got with update 5, the massive explosion could have been avoided.
We would have given them all the feedback on the test server, the most pressing issues would have been fixed. We still would have run into a few scaling problems, but due to the games infrastructure, that always has to be expected. (The main game still has much higher population than the testservers, which means that some performance problems will never be seen on the test system. ) And yes, some people would still be grumpy about a few things, but it would all be within the normal grumbling of the forums, without bleeding out to the media and without the reviews going down like they did. (For they will never fully recover. Many people gave the game terrible ratings and left. No matter how much fixing is done, many of those who left won't ever return to take another look and change their rating. )
So all in all, i still blame most of the mess not on the developers or the testers. But on management just deciding to deliver things, no matter in which state they are.