Internal testing can never iron out the glitches. Until a game or DLC gets handed to a large audience you will never know just how bad the game can be buggy. These beta tests make it easier for the developers and help solve problems they might never have actually found when only a handful of people are playing.
That laziness insult is just simply wrong. This beta should help everyone.
I agree, but 2 weeks? I have never seen a company do a beta and have it successful in 2 weeks, where it was stable upon release. That's not a lot of time to find reported issue, fix them, and put them in the main release/ and or patch.
EDIT: Not to say they won't push the release back further if needed, but normally when a company has a date set before even open beta, that means there going to do every thing they can to rush the game out on time.