In poking around the code to see what I could do to fix and/or make more sense of what is going on in general I found this message from the author I would assume:
!EVERYONE WHO GOT INTO CODE STINK!!!
!IF YOU HAVE SOMETHING YOU YOURSELF HAVE CHANGED AND YOU HAVE ANY PROBLEMS, KASYAK ALL YOUR.
!IF YOU HAVE SOMETHING YOU SKOPIPASTIT THEN PUT THE LINK ON MY BLOG, FOR NEH.
if $data['события_рада_беременность_дни']<100:
I'm not sure but I think he's not happy about people looking at his code. x'D
I'm no real coder, everything I know about QSP is self-taught (with help from the Girl Life community lead), and I wouldn't dare to presume that I could put out as much content as Avenger in the same amount of time.
And I guess it is worth noting that at least he's not using the RIDICULOUSLY convoluted structure like you can see it in, say, Perestrelo's Family Life or Unfaithful Rebirth (where it's a chore to find out which line of text corresponds to what action, and it's a nightmare to try and track down errors).
...
That said, I've been looking at the code for this for several versions and there are some bugs that have been there since at least 0.19, probably longer; not to mention that some of the grind, randomness, and oddly/frustratingly specific conditions you have to meet in order to make some events fire are something that I believe detracts from the overall enjoyment of the game (and I say that as somebody who firmly believes that giving instant access to all events in one location/with one character reduces their value and impact, so it's not like I'm opposed on principle to, say, only allowing players to meet a character only once a week if that makes sense for their progression).
His code structure is a little on the shoddy side and sometimes it's really difficult to track down what exactly he expects players to do next, even with the help of Qgen and knowing the exact variables to look for.
I don't know who would copy-paste some of his work (though he is absolutely right to expect credit for his work) and it goes without saying that he is not responsible for errors people themselves have caused by messing with the code; still, I'd argue that having access to the code has allowed more players to fix errors he has caused through oversights than it has caused player-made errors he is blamed for.
It would be kind of a dick move if he started password-protecting the QSP file - would definitely make it more difficult to play the game, especially with that weird save system (no idea why he even uses that instead of the standard QSP save system).