Because the developers don’t even try to update the game anymore.
For those logging into Bearville these days, you would see a box recording how many days have you logged in during Camp Happy Heart. According to the box, players can receive a prize every 5 days. However, the prizes are (98% positive) the same from last year. The prizes in order are an Indian Vase, Indian Rug, and Indian Bed. If I end up incorrect, I will correct any error asap.