I saw that picture earlier and was quite surprised. I don't think I've ever seen the AI play quite like that... though they used to be worse about fleeting.
Generally, the AI are good at fleeting up now. Sometimes, big fleets aren't necessary, and I noticed in a recent 2.0 game that fleets were being used to attack larger, higher priority targets while single ships and occasional pairs were sent to dispatch asteroid mines and unprotected assets.
I was pleasantly surprised by this behavior.
That said, I played a game last night on a small map with three other factions set to gifted. I had just conquered the Altarians, and they gave their last planet (bottom of the map) to the Iridium (top of the map). The Iridium sent ships that were stationed at their two planets, two starbases, and shipyard--something like 8 ships--all separately. Even though sending them as one fleet wouldn't have changed their doom, they should have sent them as one fleet.
For any devs reading, I suggest instructing the AI to prioritize gathering ships into fleets in their territory away from threats before sending them anywhere across hostile territory. At least give them a chance...