I know, the background I made is a placeholder one I threw together in photoshop. I did replace your files, including the one to get rid of the blue sphere. Both of the pictures I posted are ingame screenshots.
The biggest reason I don't like the blue is that it pulls attention away from things that need it - the ships. The bright blue screams, "I'M IMPORTANT! PAY ATTENTION TO ME!" when in actuality, the background is the least important part of the game. It doesn't look like space, it doesn't feel like space, it makes it more difficult to play, and it's not as easy on the eyes. More importantly, perhaps, like Victor said, it looks like placeholder work. Your game is even more beautiful without it.
I would like to respectfully point out that... the blue space? It's not new. Elite II tried a blue background before, too, and it was met with similar criticism. Nobody liked it. :\ The game wasn't quite as well known or successful as a result, and Braben never made that mistake again. That's the last game of his you see blue space in.
I could be wrong, but as almost all of the criticism I hear about your game is related to the blue background... I just felt that changing it might give you a bigger boost towards a successful Kickstarter. I may not have gone about it the best way, but I've been trying to help. I'm not even playing your game. I'm literally in a situation where I have no bank account and cannot back it or even purchase it after the final release. I don't care whether I get anything out of it. To put it simply, I just really, truly, honestly want to see you succeed. If there's any one thing I could change that I think would help that happen, it'd be the blue.
If you're dead set on the blue, I'll stop pestering you about it. I just really wanted to help you succeed, that's all.