The Final Fantasy XIV open beta, which should have started today, has been postponed because, oh my god, the devs found a bug!!! Obviously you can't release a beta with a bug in it, so the open beta has been postponed for an unknown amount of time.
On the other hand I am in another beta, where "being in the beta" is more of a theoretical exercise. Due to serious bugs the majority of the players are stuck at the loading screen since the weekend. Before that you could play, but other serious bugs made it impossible to advance in the game, unless you read on the forum how you could exploit another bug to circumvent the bug that prevented you from progressing.
Clearly different companies have rather different opinions on what a beta is, and what level of bugs are permissible in them.