Jester David
Hero
I see the 10 minute attunement of use in the Organized Play.
It keeps a player from swapping out 10 different magic items in a given combat.
For home games, as people have mentioned DMs can hand wave, or fast-forward, or make it a quest and several game sessions just to attune an item.
But there needs to be a hard and fast default for the RPGA and organized play.
And while 10 minutes isn't much, it also isn't too little.
Exactly.
Although, we need to test how well 10 minutes works in play, and then WotC can decide to tweak if needed while also providing slower and faster options for the interested parties.