No mate, it only wasted a few players.
The other players have learnt from past experience and from reading the Event Notice carefully that unless specified otherwise, the Event Prizes will close when the timer runs out.
Grepolis do care, they've just given you the opportunity to rake in some FREE gold, you decided you didn't want to take this opportunity, and you failed to rake in the free gold.
Other players who read the notices carefully, and who understood how the timer worked rakes in free gold.
Grepolis is definitely very uncaring... Handing out free gold for an event that wasn't in it's control, but which effected gameplay.
On behalf of the players who didn't fail to read notices carefully and who inferred that once the timer stops the prizes end (the vast majority of the players), I'd like to thank InnoGames for the event.