The resources being taxed when people talk about ggpo and 3d fighters are not online resources, they are cpu resources. Simply put, current gen systems may not be powerful enough to run ggpo alongside a game like Soulcalibur 5. If that were true then things would have to be changed for online play (this already happens in some console games, mostly fps), lower res textures, less animations, less effects. At the very least. It has nothing to do with network resources.
Even ggpo users will have encountered this, specifically with 3rd Strike. If your computer can run 3rd Strike at full fps, at whatever res, offline, no stutters, no slowdown at all, it still may not be powerful enough to run 3rd Strike over ggpo, and as your frame rate drops you will start to chop and lag both yourself and the person you're playing against. In order to play 3rd Strike over ggpo you need a system far and above what is needed to play 3rd Strike offline.
Um, did anybody even read this post? It has alot of good information; Page knows what he's talking about, so listen to him!!
While everybody's on the ggpo hype train, does anybody even
know how GGPO works, at least on a broad scale? From what I understand (if I'm right), it works on roll-back technology, meaning, when there is inconsistent connection, the state of the game loop on the systems of both players (kinda like Prince of Persia) rolls back to a slightly earlier time state to regain consistency. In other words, (if I'm right) the game literally goes back in time for a few unnoticable frames when connection falters.
What does that mean (if I'm right)?
That means that your xbox/ps3/whatever has to store(buffer) in memory and redraw several frames worth of graphical data/lighting effects/physics calculations/etc; something that the system themselves, as well as the games created for it, were NOT designed to do. With 2d and older games, this is not much of a problem, but with the latest 3d games, which are designed to push the system hardware to feesible limits in order for you to drool at its pretty lighting effects, there is simply too much graphical/mathematical/other data for ggpo to be properly implemented. Not that implementing ggpo is a 'bad' idea per se, but it's simply not possible without designing the game to do so from before even starting development (and rationalizing what graphical/lighting/physics/special effects to sacrifice to do so). Even then, I sincerely doubt it can be implemented as well as these ROM games on the net (again, might be wrong though).
What about games that use it now? Take a look at how graphically intense the Final Fight remake is (read:not very). Even the new DBZ arcade game in Japan that uses ggpo is graphically sparse compared to other modern (and more traditional) fighters.
Harada has explained this about Tekken (on the avoidingthepuddle podcast with Daishi-san), Ono and S.killian explained this about SF and Marvel; though none of these people went into real detail as to why GGPO is not feasible.
tl;dr? Stop blind support and DO SOME RESEARCH. But hey, at least blind GGPO support is actually a good thing!!