While most FFXIV accounts are less useful to those who would try to steal them than a lot of MMO accounts may have been in the past (mostly because every valuable piece of armor/ weaponry that you have is account bound if you've ever used it), people do still try to steal accounts. There's gil at the very least, and the possibility of selling the account.

I'm not very worried about security personally. Statistically nothing is likely to happen to me (or any one user in particular), but some accounts will surely be compromised and have been already. In any case, the free teleport to Mor Dhona (or wherever you like) is more than enough reason to tack on 15 seconds to my login times.