I really doubt they have different proc gen algorithm tweaks just for Survival Mode; you've probably just not had great luck with planets.
But to your question, Survival Mode is basically a roguelike. I feel that Hello didn't intend for this mode to just be a harder difficulty level, but to be a separate experience. There is no payoff at the end, it simply exists to test how long you can survive for. To have that constant feeling you're never safe, to not get comfortable. Maybe this mode would have a better long game if Hello's original idea of the universe where systems get harder and harder as you go towards the center had made it into the final version. But I'm sure they're not done with it.
And I don't really think Normal is too easy. I feel like I'm constantly scraping by. I landed on an ocean world last night looking for Rigogen. I landed by a shoreline. When I jumped out of my ship, I immediately heard the screams of four animals the size of large dogs barreling towards me from all directions. Bite, bite, bite, knocked all over the place. I had to jetpack into the ocean to escape them. There fortunately I found some rigogen, but the ocean floor was deep and my oxygen was quickly depleting. So I rocketed back up and back onto the shore to tank up. Annnnd more angry dogs attacking me on the beach. Then came the freezing rain storms while I looked for exosuit materials. Ran to a cave. Back into the water. Rinse and repeat.
So while I rarely feel like I might die at this point, I definitely feel like each excursion is a challenge to overcome. And that is a satisfying 'normal' experience.
