I would certainly say it's bad if it was dropped when it's part of a stretch goal. You met stretch goals but it was not delivered. For whatever reason, if it was part of a stretch goal it should not be dropped for whatever reason. You should not promise ANY goals if you can't seem to meet. At least that is what how i look at things.

I'm around 90 hours in the game but i would say that Day Night Cycle is not really a necessity. It only add immersion that NPCs have schedules and probably some night missions, etc. I would forgive Larian if i'm a backer but still one should not promise something and failed to delivered especially on a financial funding.