Majoru Oakheart
Adventurer
How do we know that a cursed item doesn't take affect until the character attempts an attunement?
That's definitely the implication in the article. It says that some items have drawbacks when attuned(i.e. cursed or at least slightly bad in some way). You can identify an item to see it's drawbacks before attuning.
Though, it does seem like identify is pretty useless. Assuming that cursed items are far and few between, it seems pointless to cast the spell on every item you find under the assumption that it might be cursed. Especially if it has a cost of some sort to cast. Unless nearly every item has some sort of drawback even if it's minor.