You get overly fussed for nothing. If you like the style, just go and enjoy it.
Cartoony is not a derogatory term. It's just a realistic depiction of NMS' looks.
And there is nothing wrong with you liking it and me not liking it.

I even said why i dont like the cartoony looks in NMS - the vegetation and critters look too much like Spore.
The sky, take off and space flight looks like space themed cartoons. Ships too. Space stations. Should i go on?
And that's a nice collection of book covers, i love them (my teenage years happened in the eighties and i grew up with that style of sci-fi art and book covers - mostly from the golden age of our '55-' '75 prints), but that still does nothing to change how NMS looks, so it doesn't really help your cause.