EA likes its DRM, GOG doesn't. That's a big sticking point on System Shock 2.
Well, to be fair, we don't know that. We know that EA use DRM on their new games, but so do most companies here. There are several companies on GoG who have been known to use Starforce and Securom on their releases (not that I hold that against them, I'm pretty fed up with the the anti-DRM hysteria to be honest, I'm just pointing it out). So the fact that EA use DRM-solutions on their new releases doesn't have to be relevant here.
My guess, though it is only a guess, is that EA know their back catalogue is worth tons of money, and they're not yet convinced that they should "turn it over" to GoG. They have traditionally been very keen on maintaining control over their IP and products - they did not like Xbox Live to begin with, they wanted their own digital distribution platform instead of using existing ones like Steam, et.c. So basically, I think GoG will have to really prove itself before they will consider it.
Considering that EA executives have made many statements in the past regarding their need
for DRM and other copy protection schemes and that EA has been one of the most vocal proponents of DRM, I'd say it is very fair to say they like their DRM. Even when they release a game as supposedly "DRM free', they release it on Steam, which is DRM in and of itself. When called on that, they revise their statements to say "no DRM beyond Steam's own DRM". Unlike other companies that have used DRM schemes in the past, EA has not heard their customer's complaints and continue trying to squeeze more and more restrictive DRM into their games, while those other companies instead try to find ways to reduce the restrictiveness while maintaining the security. You or I may not necessarily "know" that EA likes its DRM, but in the absence of any evidence to the contrary, it is still a valid conclusion.
The big players have hundreds of games which didn't see rerelease in years and probably won't ever see (boxed version at least).
so what is stopping them from dumping one or two of less popular games as an experiment? if it fails (very minimal sales) there is no real loss. but if it succeeds there is lots of monies to be made. Not only from sales but from new franchise which could originate plus it is also a good advertisement for a company.
I believe that is exactly what JoWood is doing right now.