I was the same as the OP for a long time. Just did not see the point.
Sandbox games didn't appeal to me either.
Basically
if someone had said to me the aim is just not to BUILD but to SURVIVE it would have made more sense. You have to survive because there are monsters that come at night to get you. If you haven't built a good enough place they'd find their way in. If you haven't built a
strong enough place they'll blow holes in it and destroy it.
Your best weapon is light. Torches. Light stuff up to keep them away, if they do come close enough there are other weapons you can make - swords, bows and arrows, tnt traps to let them have it.
So you have the ability to build things using the resources of the land? Fine. First you'll build a hut. But then in the next day you'll have more time and confidence so you'll want to build something a little bigger and bolder... so you'll build a house. After a while you'll get bored of that and will think of building a stone castle. Maybe with a ditch and a moat. And maybe a throne room with a library and burning torches. Maybe an underground dungeon. You'll give yourself projects. All the while trying to keep the monsters at night out who could come in at any moment.
And remember that each world is randomly generated. No-one will have the same world as you. You have deserts; green fields with lush vegetation; maybe some snowy high maintains with streams and pines. The same principle applies though, you have to survive wherever you are.
Now if someone had said that to me at first... I would have liked it better. And since playing I have build not only forts but large wooden oriental temples with pagodas, water features, wheat farms.... and even a strip club with black obsidian walls.
Watch this short video and it will maybe seem more appealing. You just carry on doing stuff, it doesn't get old.
