Slight spoiler warning.

As you play through the game, it pretty quickly teaches you to explore every nebula, as they contain stars. As you get further into the game, there are two very large nebulae, which obviously you are going to explore. They slow you down though, so this is an arduous process.

And then it turns out that they are almost completely empty. Just one star in each with nothing to find except some log messages implying that those nebulae were deliberately placed to frustrate the player Who thought that was a good idea?! In a game that's 99% about exploration?!

It marred my experience of an otherwise very enjoyable game.

I have to agree. There are about 6 of these star systems, I think?
One of the nearby planets gave some resources of which I already had a lot of, and the other 5 had nothing.
You'd expect something good to find for taking the trouble spending so much time exploring these horrible nebulae.

And the log said that the captain never believed there was nothing in this nebula, and just kept searching. ;-)

Wait... maybe you were that lost captain!

Spoiler:

In north gray Nebula there are 3 planets, telling the story of a captain who never gave up looking for valuables in that Nebula. You have to be close enough to even detect these stars. They are totally optional. To save your nerves and time, use: F11 console and enter MarkAllDiscovered(); then reload last save.