Gambling, porn and drugs are not shady unless abused, like anything else. There is nothing morally wrong with doing any of them, however they are categorized as "sinful" from a religious perspective which has made its way into law. They are considered illegal or crimes in many places, to which there is no victim.
If you look at it from the wider perspective of society as well as the beliefs of those who occupy positions of power and make the laws, then that is a minority opinion. Whether we like it or not, most people still believe that those things are wrong even if most members on these forums (including me) might not subscribe to that belief. If Bitcoin wants to become mainstream rather than being merely confined to libertarian circles then from a marketing point of view at least, I think it makes sense to de-emphasize those aspects.
It's interesting to see that you mention Just-Dice and Canadian gambling laws. What's funny is that the we have lottery and gaming corporations in Canada run by the government. They are even able to market and encourage lottery and gaming to the mainstream through TV commercials, radio, internet ads, etc.
We have state-sanctioned lottery games here too. Usually the revenue generated from those go to schools and community projects. As I said, gambling is probably the least controversial out of the so-called "sinful" activities that I listed.
There is nothing morally wrong though, as it brings harm to no one. So whether or not these things are taboo or against what certain people stand for, doesn't mean anything to anyone else. It's a belief system that needs to be subscribed to.
Porn/prostitution with consenting adults has no victim. Gambling has no victim. Drugs has no victim. You can argue that people that abuse these things can harm themselves, but you can harm yourself with anything done outside of moderation.
So to say that gambling is wrong, but if the government owns the corporation, then everything is fine and it's not wrong anymore, is exposing an incredibly stupid mindset. If someone thinks its wrong, then simply don't do it. But to take freedom away from everyone else that doesn't share that same thought, doesn't make any sense.
A vegan thinks it's wrong to eat meat/dairy, so should eating meat be illegal for people that don't share that belief? As stupid as it sounds, it's as legit an argument as gambling/porn/drugs, or maybe even more so as animals are being killed.
Anyways, back to bitcoin, to start restricting its use based on what the transaction is for doesn't make sense to me. Pre-bitcoin all shady transactions were done in FIAT, and it's likely still a significant majority that's done in FIAT, and it doesn't give FIAT a bad name.