If things are going how I think they're going, Minecraft will lose its charm that got me interested in the first place.
Yes, but building all the time also loses its novelty after a while. I'd like to do more than just build an empty SSP city or massive castle, then return to my cobblestone generator when I run out of resources. I'd like to do more, like explore things such as ruins (or in this case, strongholds) or trade any junk items I've hoarded away to NPCs and save up for things that would benefit me.
The watermelon and pumpkin growing is give or take. Pumpkins only serve as helmets and an enhanced torch. If watermelons possess something more unique or useful, the cultivation of them won't be too worthwhile.