I added the destruction of the leaf blocks simply in case people felt that fruit producing trees would make the game unbalanced.
It also makes you have to tend to your orchard as well. If you have a tree that perpetually produces fruit, it takes away the whole farming lifestyle for those who enjoy it.
I am somewhere in the middle. I enjoy farming. Harvest my crops, replant them, wait for them to grow. It gives me something else to do other than just...dig block. Place block. On the other hand however, I also wouldn't mind not having a high maintenance farm/orchard. So. I am ok either way. Have it break blocks, or don't. As long as I got the trees, I would be happy.