There's nothing wrong with a Curse that essentially allows you to pull a Curse out of your deck at the beginning of each of your turns and play it for free. It's cool that they came out with a card like this, as it would seem to make some of the more expensive Curses much more playable.
What Curse of Misfortunes does is very good in theory, but there are a couple problems with this card. First of all, it costs 5 mana, which while is probably a proper cost for what it does, means that it doesn't hit the board for quite a while. Also, you can't attach more than one of the same Curse to a player using this effect. That's what really kills this card.
While in theory it does quite a bit for you in the long run, it's not really worth the investment when you could just play another Curse instead. The design is cool, but game play wise, Curse of Misfortunes just never really worked out. It's a bulk rare, sadly.