Fine, you're not a min maxer, an/or you do not care about being efficient with skills. We're not all like that. In fact playing on tougher difficulties you can argue you are forced to be very efficient because you are in an arms race with the enemies. Example:
Playing 2-player co-op, Insane. We know Demolishers will arrive by day 21 horde. We have 21 days to get our base design up. This means we need 100k Concrete and a crap-ton of Steel by then. Friend will spec into Int and go straight for Steel, I will spec Str and go straight for Miner69er and Motherlode. We *have* to do that. There is basically no point in MIning without 5/5 in both those skills, given the rate I need to get Stone.
It's an extreme example but the point remains. Mining with few or no points in those skills is extremely inefficient. Whether that inefficiency bothers you or will actually turn into a genuine LIABILITY depends entirely on what kind of player you are and what difficulty you are playing on.
Yet again I find myself having to say the same thing to you, Ghostlight - it is nonsensical to be choosing to turn up the difficulty and then complain about how difficult it is.
Maybe you've gotten too used to having an easy hard mode - up to alpha 16 there were too many exploits and short cuts which made it possible and, in fact, simple to be able to turn up the difficulty without actually making the game significanlty harder. Those days appear to be over.
You don't *have* to do any of the things you list; you *choose* to play on max difficulty, you *choose* to build a base, and *choose* to fight the horde in it, you *choose* to build a base that requires 100k concrete steel, and *choose* to max perk into those skills for max efficiency.
You could just as easily choose a lower setting, choose a different base, tactic and / or level of efficiency and still enjoy yourself - but obviously the challenge will increase on higher settings and you will have to make more decisive and better decisions to survive - presuming you are *choosing* to consider dying or having your base destroyed as a game over or situation you are not willing to accept; but everything which you and others in this thread - and others - is being dictated not by the game, but by the players choices.
By going into your game having already decided exactly how you are going to play you have restricted your own options; it's like playing Fallout NV deciding you're only interested in energy weapons and power armour, and then complaining that there aren't enough energy weapons and power armour in the early game; before continuing to run about using only a laser pistol and no armour and complaining that the game is too hard because bandits with rifles are killing you.
THAT'S extreme, but it the point remains, whatever you choose to do, and whatever you choose not to do has consequences; and the players here appear to be choosing not to take advantage of the opportunities available to them out of a play-style choice - which is fine - but to then construe that those opportunities should be removed in favour of ones which suit their own min/max high difficulty choices is weird - IMO.