Point the first: eXistenZ equates its VR game with sodomy. Ted says he doesn't like to be penetrated; Allegra sexily lubes up his "tight" bioport before his "first time"; of course, when we get a look at the bioport, it looks like an asshole; then there's the really great bioport sex scene, in which Ted tongues Allegra's bioport, she responds with surprise, then arousal, then Ted, you know, fucks her in the bioport.
I guess this might be a somewhat less pressing question for the film and for the nature of VR games in general (it's in this context that we're putting eXistenZ in apposition to Snow Crash) since it's Cronenberg at the helm. Anyone who's seen Videodrome will remember the VCR-vagina that spontaneously appears in the middle of James Woods's chest, and how James Woods masturbates his VCR-vagina with a gun and then loses the gun in said orifice. It's weird and creepy and typically Cronenbergian.
But I think the stakes are somewhat different in eXistenZ. In this case, the anal nature of the bioport suffuses Ted and Allegra's discourse. For the first twenty minutes or so, any off-hand remark about Ted's gaming inexperience is also a prurient sexual remark, in which Ted is figured as the submissive ("passive" would typically be better, I guess, but seems less appropriate for describing the dynamics of these scenes) partner in anal sex--e.g., "You'll see how natural it feels." Under other circumstances, such lines wouldn't have the same bizarre sexual charge that they do here.
The film has clear anxieties about the use of VR; in the final scene, Ted and Allegra accuse the game Evgeny of bastardizing reality. In a way, it makes sense that the sexual appeal of VR would be the sexual appeal of sodomy. In Christian history, the typical reason for banning sodomy--which can include anal and oral sex, obviously--has to do not with how you do it, but why; sodomy opposes reproductive sex, which is regarded as the only good form of sex. In class, we talked a little about the seeming absurdity of wanting to accumulate Linden dollars--what's the point? is the standard take. Put value-intensively, one might say, why not do something *actually* productive? Instead, we could think of VR commerce as a sodomitical commerce. Whatever threat inheres in VR is the threat of the nonproductive.
I'm interested in this idea that the true motivation of VR is sexual. Are you saying that VR's lack of 'real-world' productivity parallels the non-(re)productive act of anal sex? It makes sense that a director might link two concepts that he finds so closely related. But this doesn't answer why would people want to do it. For the experience of being un(re)productive?
Let's go back to the idea of VR as vaginal sex, like we talked about in class. Ted (and I think you're right to draw him out as the best example) is male, and thus his participation elicits the question of anal penetration, but VR is about placing yourself in imagined situations -- it wouldn't be the first time a male wanted to experience sex as a woman. I think both metaphors (VR as anal or vaginal penetration) agree that users desire VR as a chance to experience the unfamiliar -- what they can't have or don't allow themselves in the real world.