I'm pretty sure it was concluded that items should be turned off for competitive play since there are very few tournaments where items are allowed.
Actually I'm fairly certain the outcome was items are to be banned from competitive play due to their random and unpredictable effects and placement. A pokeball could spawn next to the person losing and turn it into a win depending on the pokemon or you could be mid combo and have an unlucky bob-omb spawn on top of you mid attack and kill yourself with it. Theres no way to effectively control where and when they spawn so its basically taking the game and forcing you to play against the games mechanics instead of your opponent. Not to mention 90% of the items could be an instant KO when used properly. When the items took more stocks then the characters themselves it just became silly to use them.
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