Well, in this case you have "I don't notice the grind because I just play the game". I mean seriously, it's like you never played a well-designed JRPG in your life. Take Phantasy Star IV - random encounters up the wazoo, every step of the way from one place to another. And completing quests and missions involves a lot of getting from one place to another, so you never spend time "grinding" - you're just fighting your way through the questline, and you're never hideously understrength to tackle a given obstacle in your path. Unlike, say Phantasy Star II...
Usually that is usually for padding and indeed I've played games that did it well and games that did it badly (USUALLY by making the grind the game... Dang do I wish The Last Remnant was a better game... they were really onto something).
I actually like a bit of grind in a game (though I usually try to blitz an RPG near the end apparently... probably because that is when the story gets intense.). I just find Starbounds to be a bit too much, and mostly boring. There are plenty of games longer than starbound (I probably could have got to tier 4 in 32 hours), but they have a lot of content along the way to keep you interested.
Mind you the opposite has problems too... (Having everything from the start, makes things get boring later)
It's not a question of making your own fun. It's a matter of being aware of what troubles you and whether the source of that is the game, or merely how you play it. If you're regularly losing massive amounts of ore to dying in the hellish depths of Delta Brandywine Jugular IV, perhaps you should consider stomping down on your own sense of curiosity and strife and pull out with what you have before you lose it to another needless risk?
To an extent, I mean you are right from a practical scale.
Yet they should still give you the tools to make those risks feasible without requiring you to... for example... build a shaft for every planet you attempt this on.
Each Tier should take long enough, if you are gunning for it, to give you a taste for the themes and challenges for that tier, as well as teach you the new aspects of the game one by one... before making way for the boss. While also long enough that if you are taking your time, you should still stumble upon the tools you need to advance while also getting a bit more out of the experience.
My complaint is if you are honestly attempting a tier the ONLY way to advance before the tier gets stale is to immediately drop into the depths of hell (or Asteroids, I keep hearing they are mineral rich) so you can find minerals in abundance... or Deserts. While if you are taking your time, it still takes way too long.
Edit: I did delete a rant here, mostly because I didn't want to throw this thread into more hostility. It did directly respond to Naxza