Not really. Should it have been in earlier, yeah, planned from the start, sure. Is it a bad decision to implement the system as soon as it's available, of course not.
The main "bad decision" that springs to mind for me is the email-change form that let folks spam it. That's day-1 stuff (though I'm no IT guy). The fact that tons of other databases (including Battlenet and some game-magazine forums and such) were comprimised and lists of folks password were out there isn't really their fault.
The authenticator system is one of those things that I think should just come in the box (for versions that have boxes) for all MMO's now, but it's an added expense that they want to avoid tacking on. The email-verification system worked fine for me. But, really, anecdotal evidence is useless for a reason. My friend has problems with TOR, WoW and now GW2 crashing on his PC, I do not. He constantly bitches about all of them to me, and my only response is "can't offer any help...". Plenty of folks had issues, plenty of folks didn't. We don't know what the rate was, so assuming anything else is a bit pointless.