Aignur: You didn't ask that question before, so it's not asked "again", but that's beside the point. Responsible use of abandonware is a term used primarily to distinguish sites like Abandonia and the former (not the current) Home of the Underdogs from obscure Russian scam-sites that offer you half the moon, but end up taking your credit card details.
Okay, let's take a look at those three criteria:
Unavailable on retail market and no longer distributed by its publishers nor by legitimate retailers in any form:
So they don't even follow their own rules? Amazon and eBay tend to have a lot of these collections, and those are pretty legit sources. Many of them ARE retail shops that are selling their stock online (that is how I got Redguard a few years ago).
Official support for the game must have been dropped both by its publisher and its developer:
Okay, ignoring just how little this is worth (84% of games that are more than a year old fall into this category :p), what defines "support"? Patches? Sales? A desire to hold onto the IP for future use?
Third, (lots of crap that basically says "nobody will sue us")
This is the "covering our asses" clause. I don't think we need to argue about how this makes them responsible or moral or ethical.
Again, what is so "responsible" about this? All it means is that they are REALLY terrified of being sued (a side effect of being popular). By those definitions, very high-class brothels and auctions of illegal goods are also "responsible" because they have VERY strict criteria regarding behavior and clientelle so as to cover their asses.
Aignur: You seem to have missed something, so I'll highlight it for you:
Okay. How is providing copyrighted material legal? Or are we going to play the "I don't think the law is moral, so I am going to do whatever the hell I want" card again?
And again, how is giving away the hard work of other people responsible?
And I am just going to cut you off before you play the "There is no way to send the developer any money, so it is okay to steal it" card. As was mentioned in this/another thread, if people really care about making sure the creator gets supported, send letters full of money.
Beyond that, do you honestly think that half the developers for the games GoG sells are getting their cash? Hell, do you think half the original publishers are getting the cash? Nope, it is just the guys who own the IP currently who get the moneys. So if the real issue is "Jim's Discount Software shouldn't profit off of Wizardry", then you guys better keep pirating stuff even after GoG inevitably gets a hold of all the Wizardry games and makes me a very happy person.
If you want to argue it is "morally right" to steal the hard work of other people, feel free. I don't see the point in arguing that following "morality" is a really bad way to handle society (you would think someone who likes video games, many of which contain gruesome depictions of torture and murder, wouldn't play the "morality is all that matters" card, but whatever :p). Throughout history, there have been plenty of Robin Hoods who redistribute the wealth. Many of the existing works of art were saved from destruction through rape, pillage, and thievery.
But that doesn't mean that the guys who stole the pretty paintings (a month before the embassy exploded!) were out to save art. Maybe some of them wanted money, and maybe some wanted fame and prestige. And maybe some just wanted to sow anarchy.
And THAT is my point. ALL abandonware sites (again, except for "the good ones" :p) are out to promote piracy. Simple as that. Maybe they also promote other stuff, but at the end of the day, they are pirates.