The trouble is, if you go too far towards being polite, the label that applies is "doormat".
Charles StrossToday, we see some "file sharing" sites that rely on fans uploading cracked copies of ebooks, and which then make money off those books by charging for downloads (via cash subscriptions or advertising). Again: I take a dim view of this. They're making money off the back of my work without paying me.
Charles StrossWriting your own story around the same ideas is not plagiarism; at worst, it's being unoriginal.
Charles StrossAn important factor to note is that it's rare for anyone to sell a first novel written before they turned 30-35; long-format fiction tends to require a bunch of experience of human life that takes time to acquire. So your average mid-career novelist is in their forties to fifties!
Charles Stross