While I hear what you're saying, this is practically a textbook example of the Slippery Slope Fallacy (tm)
"If we let them ban a rape porn 'game'... it'll lead to massive censorship of all entertainment media!"
Reality check: porno games (from the "dating sims" to regular games with gratuitous nudity and sexual themes pasted in) have been around long enough that they're their own sub-genre. This would be like saying if we ban Puzzle games, all games would be banned. Even if we banned all porno games (rather than just this one title), would that really affect most gamers? Or even most porn-enthusiasts for that matter? Like most obviously "adult themed" material, these titles are typically low budget and not found in mainstream retail stores (or mainstream theaters for movies) anyhow. People who want such things will know to look in the "specialty" shops or order direct from the publisher. The stereotypical fear that somehow it'll be sitting on the shelf between "Barbie Makeover" and "Pokemon" is unfounded for that reason.
Jack Thompson is definitely a joke, he's just out to get attention and money by inciting "outrage" to the point of self-parody. But the odd person who hasn't heard of him might be fooled the first time. The only time gamers gotta worry is when its a bunch of big wigs getting into the "censorship" crusade (Senators, wives of Vice Presidents, that sort of thing).