That's probably because the game is made with a Unity Personal license, for small or cheap studios only. With other licenses the splash can be disabled.
One of the best games ever made, Outer Wilds, was done in Unity. Dyson Sphere Program is an excellent factorio style game that's very well optimized. I do not share your same trepidation on seeing the logo (doesn't move me in any direction, both some of the best and some truly awful games have been made with it).
Usually that hesitance is because a lot of amatuer stuff has been made using Unity. But when in the right hands, it can feel like it is its own thing but it is easy to be hesitant after shoveling through so much trash.
Yeah, because it means the devs don't have a few thousand in the budget to support removing the logo, so of course they don't have the money to pay people to performance tune the game.
https://docs.unity3d.com/ScriptReference/PlayerSettings.Spla...
This selective limitation has probably had a significant negative effect on Unity's reputation.