Looking at that screenshot, I would call that a tough, hard-earned victory incurring significant losses in my resources. Since that fight is a tough one that 'gates' you from a new area, one might decide to roll with it. I know I've made through that fight in worse shape in some of my playthroughs. But obviously, if these kinds of costs (in terms of consumables you had to use and all the health you had to lose in order to win) are being incurred every fight or every other fight, then I would think, hey, my guys are really struggling here, I need to change something - difficulty, strategy, build. I wouldn't really think, "Oh as long as I lose a crapload of health and use several of my consumables I'm doing fine."
Again, it's got nothing to do with whether the game is 'too easy' or 'too hard'. It's just really simple - I play this game an hour, and I quickly realise that this is not a game where you can rest and heal up and buy healing potions whenever I want, I realise that I can't grind against easy opponents for XP. So I realise that it's not enough to 'win' with 1hp left, I need to think about the maximal conservation of every resource. So I wouldn't think, "hey by using a lot of my limited resources, this was a cakewalk", I would think, "man, I had to use a fire pot to get through that, could I have done better?" or, "Well this particular fight I needed to use everything I had, but now I am thinking how to use my new skill points to make sure I'm not on the ropes like that next time."
There's really nothing super mysterious going on here I think, it's just your expectations are not in line with the reality that your guys face within the game. (I'm not saying that's 'your fault' or 'the game's fault'.) When I pick up healing pots in BG1 I quickly get a sense that they're not super rare or anything, but I can't really afford to pop 6 of them every single fight. Equally, nobody ever tells you that this scroll of disintegrate is really rare, but you have a general awareness of the game economy, so you know not to just use it for shits and giggles in the very next battle.
P.S. Part of this is because the entire game's premise is that you're stuck in the bottom of a fucking dungeon with jack shit for survival. You're not an adventurer, you're someone who's not supposed to have a shot at getting out. Your environment isn't a series of cool set pieces for swordfighting, it's a long and gruelling dungeon that you have to keep hoping will have enough stuff to last you long enough to escape. If you don't like the fact that you need to try and not lose HP and such, there's no shortage of RPGs that aren't designed this way. And no doubt even Colony Ship won't be quite so tight and sparse from an attrition point of view.
