I'd be pretty pissed if someone stole my source code and people were all happy on gaming forums. It's one thing to see lost prototypes, but actual source code of finished games? That's not very nice
I agree with you. I like looking at things like the cutting room floor because it allows people a peak at certain unfinished or changed aspects in games, but I feel a little uneasy at people being so outwardly positive about what is effectively the proceeds from a cyber hack.
I would point to Dylan Cuthbert's response above and I can begin to understand his feeling of dissatisfaction towards other people going through something that he worked on several decades ago in such specific detail, particularly when it relates to stuff that he worked on and has long forgotten about like certain internal development tools.
Without making too much of a point of it, I would feel really uncomfortable if long forgotten artifacts from my own work were suddenly released to the public domain. I don't think it's a question of being overly secretive or not welcoming the interest and enthusiasm from die hard fans. It is really cool and interesting to see some of this stuff come to light but I think people who worked on this are entitled to feel uneasy about it all being put out there without any means to directly respond outside of speaking publicly or seeking legal action or some other intervention.
If you work in an environment where you might reasonably expect that personal records, internal communications and pieces of your work would come to light in an unfiltered, unedited way then I think you are in a far better position to prepare yourself for that eventuality. I don't think a commercial software developer or publisher is that kind of environment. Even free open source software often starts off as something that is private and worked on by a small group of people in relative secrecy or anonymity before it is made available to a wider environment in an edited, sanitised form.