I think the idea of selling old games is valid. Most of complaints here are refering to the very old games, made for dos, and are easily available for free on the net.
But there are some windows 95 games that don't rely on Dosbox, work badly in compatbility mode, and though you can look for the solution of trouble on the internet, it's sometimes very hard, time cosuming and not entirely 100 % solving.
For example, Riven (Myst 2) on windows vista/XP.
There's no Dosbox or Scummvm helping here. There are workarounds, but they're not perfect.
If GOG sell these games for a low price, manage to make them work on Vista/xp, with dosbox or not, offers some extras like manuals, maps, making ofs, etc, Ok. the only thing is that they most deliver what they promise.
about paying something for some dead company product, who cares? This happens in new, released games as well.
Like people who bought fallout 3 from bethesda and it being a property of interplay in the past.
This brings the DLC issue. In fact, DLC issue almost aways refers to bethesda. That they're charging for shit add-ons. Well, some payed for the shit full game an expensive price.
DLC is what was called "expansion" some couple years ago. Everybody payed for expansions. A lot more that a DLC costs.
And finally, not only old games are avaible for free on the internet, but new games also are. New games it's called piracy, old it's abandonware, which has a feeling of it being "legal". But what matters in the end is if you are willing to pay for a game or download it for free.
About wizardry, yes, I forgot that they release lots of games till this day that bears the franchise name. The even keep the original logo. Probably the japs own the franchise now.