Interesting points. I tend to get bored VERY quickly of games without goals. That's why I don't like Minecraft. There's literally nothing driving me to progress. Terraria at least has bosses to beat and new biomes to reach. I think that's enough of a push in the right direction for me. But Minecraft really put me to sleep in no time.
Well, that's the thing about it: I like that Minecraft just sorta causes new goals to appear out of the air, IF you allow them to.
Typically when I start a new world, my first goal is to get a Nether Gate operational. First major goal, anyway. So, the first minor goal becomes "Find diamonds" or sometimes "find a lava pool" if I'm getting impatient about the diamonds. Along the way towards getting this, there's typically other minor goals that appear. I need coal to advance into dark areas. I need iron to make a pick that can actually dig up the diamonds. Or I need buckets if I'm going the lava route (which also means iron). On the way down, maybe I find an abandoned mineshaft (dungeon-like maze area, typically filled with poison spiders and the spawners that create them, nasty things). New goal: Explore the mineshaft maze, there's probably diamonds in there but also other things. Sub-goals in there tend to be finding and destroying spider spawners, and gathering rail tracks. Other goals may appear while exploring the maze depending on what the RNG does, and what other things I may be wanting to accomplish overall. Once I have a gate functioning, more goals appear, typically involving the Nether Fortresses (other dungeon-like area filled with fire-based mobs) because I want a very specific thing found in those. In doing that, I need to explore the Nether, I probably also want to set up a farm that involves chickens (because I need arrows in that place), which typically finding a biome that actually has enough damn chickens, which might also mean setting up more gates so I can reach said biome sometime this century, and other things. In other words, the game tends to give tons of goals, but it's up to the player to decide on what they are, and how to go about finding them. Instead of terraria's extremely linear approach (which I don't mind, but it does get exceedingly repetitive to me). The one and only problem to me is that Minecraft does NOT give you any real explanation on how it works overall; the console versions have a bit of a tutorial, but it's very sparse, and the PC version doesn't give you a damn thing. You have to know enough about the game to understand all of these possibilities, or you wont know that any of them are there. To be fair though, Terraria does this too.
And then it just gets more and more loopy with modpacks, where the complexity just goes berserk. It can become overwhelming with those.
That being said, the game DOES have bosses to go after for those players that really want to. The quest towards the Dragon is a long and tangled one, with a million things that must be done in order to advance through that, but the reward of opening up an entire new zone filled with some of the game's rarest items if you can manage to do it. There's another boss, the Wither, the most dangerous thing in the game, but I usually don't recommend trying for that one. Lastly there's the Elder Guardians, and you have to go into a particularly nasty type of place to deal with them, I usually don't go anywhere near that hellhole without massively enchanted equipment and about 5 sets of potions on me at once, and even then the chances of dying are pretty high. All those underwater deathrays.
I'm totally incapable of playing vanilla minecraft, personally. Not enough stuff to do, and building for beauty's sake doesn't interest me much.
No, I play heavily modded minecraft to make the game play itself. One of my favorite things is setting up Thermal Expansion ore processing, usually fed by a quarry. Then I make it all self-sufficient so that it'll run until it runs out of storage space.
Generally I play the massive modpack aptly named "The 1.7.10 Pack" since it has a copy of nearly every major mod updated to 1.7.10.
Yeah, I've seen plenty of others say the same things.
I'm not fond of automation myself, I get bored of the machinery stuff pretty fast. My thought is usually "I'll go questing for the damn ores myself, thank you very much".
Also I'm not too fond of building stuff for the sake of beauty anyway. Not that I'd be any good at that. I tend to make practical structures that end up being a bit of a distorted mess.