I'm gonna chime in here, just in case someone is keeping score. I think this topic (morality) might be the most important debate of all. Sorry if my post is very long, but for the most part this has been a great thread. Also, this is a general post, not aimed at anyone in particular.
My short answer is no. Playing poker, or gambling in general, is not immoral. I don't believe many things in isolation are immoral. Unfortunately, the world simply isn't that black and white.
Take the most extreme example; Murder. Almost every society and civilization in history has scorned murder and made it illegal - those that allow it exist in a state of anarchy and would not survive for very long . But at the same time, almost every society has found ways to make exceptions to even this rule.
We murder on the battlefield, in the temple, and sometimes even in the courtroom - supposedly the domain of justice. Ethnic cleansing and genocide have often been endorsed by church and state. This facts make it clear that in certain states of nature morality is vague at best.
Obviously I am not comparing gambling to murder, that would be foolish. But to consider certain actions in isolation as immoral is stupid and counterproductive (there are things that even I regard as evil - rape and murder spring to mind, but I've wandered off topic enough).
In my opinion (and the opinion of many respected scholars), the root of morality lies in freedom, and the very definition of freedom is a persons ability to pursue a goal or desire without external coercion or constraints. Put simply, if your actions do not harm others, then you should be free to perform such actions
If someone chooses to sit into a game of poker, is not coerced (have you ever heard of somebody forced to play poker?), and gambles with money of his own possession, then who am I to deny him that right? I am not the moral arbiter of the poker community, and neither are you. How many books did you read before playing your first hand? For how long did you play and lose before googling poker strategy? We all started out as losers, and many of us still have no edge in the game.
Have you given up drinking alcohol? Smoking? Consuming salt, sugar, and trans fats? Are you sure none of your clothes were made in sweat shops? Do you drive an electric car, or walk everywhere? I applaud you if you have, sincerely I do, but I hope you do not picket bars and nightclubs, or blog about the evil chocolate factories and how Ford are solely responsibly for global warming. I hope you do not lecture relative strangers on the threat of cancer and diabetes, simply because they enjoy wine and gummy bears.
This is the moral argument against banning poker, or regulating which consenting adult may play and who may not; Who are you to tell them that they can or cannot do with their time and money?
What about prescription medications? A certain percentage of people who are forced to take meds for crippling pain are at risk of becoming addicted, or being led to drugs such as heroin and Oxycontin. Admittedly the percentage is low (but I'm willing to bet the figure is in the same ball park as, or higher than, gambling addiction). Furthermore, addiction to powerful pain killers is extremely hard to beat and very damaging to the human body, and the habit is far more expensive that heroin or meth would cost the average user.
So should we ban paracetamol? If you think I am comparing apples to oranges then think again. OTC pain medication overdose is one of the most common methods used in teenage suicide attempts, and said attempts often lead to death or organ failure.
Cannabis is similar. There is little evidence that marijuana is harmful, aside from the obvious risks of smoking (so why not eat it!!) or doing something stupid like taking it before driving or taking it every day. Anything in excess is dangerous, even clean water. Marijuana is infinitely less harmful than tobacco and alcohol, and is often more effective at treating minor pain and certain medical conditions that prescribed meds. Yet it remains illegal largely due to ill informed traditions and taboo.
Now most fish play very small stakes poker, at NL10 - NL100, where they get some excitement with relatively lower risk. Further, most fish play for a very short time often "trying out" poker, losing a few hundred or thousand over a few months or a year before simply giving up. Almost every player I know has a solid income away from the table, and gambles very little relative to his living costs. Very few of them bet on the table games either, although there is a culture of sports betting in Ireland (I'm Irish) which many believe is very harmful. Put another way, poker, and particularly the micros, are the marijuana of the gambling world, or maybe even the aspirin.
This is the rational/practical argument in favor of poker; We have to trust people to make their own decisions, and trust that the decisions they make are best for them. You may see a guy losing a couple of hundred bucks, but he might just be a new player, finding his feet. He could be wealthy, and doesn't care about the relative pennies he is losing. Or, he might just be blowing off some steam, and doesn't really like roulette, or watch sports.
The gambling industry is a very profitable one, creates many jobs and provides a fortune in taxes and revenue. There are many worse industries out there, such as the tobacco corporations and arms trade. Why waste your energy trying to prevent people from making a harmless mistake (that they might enjoy), that most will make in some form anyway, and will probably learn from along the way. The truth is that most losing gamblers stop before they do any lasting harm to themselves, and the ones who don't will simply find another outlet for their addictive tendencies.
Of course you will have addicts and egoists who cannot accept that they have no chance, and if you believe you are playing with one then fine, pull him aside and express your concerns if that will help you sleep at night. They deserve help, but they are not the worst of humanity, far from it, but poker is not truly the root of their problem, as the object of abuse rarely is. But while you're at it, make sure you show up for the next protest against the conflict in Ukraine, and join the fight against ISIS. Campaign against nuclear arms and the weapons trade. Celebrate Prince Charles' decision not to represent the interests of the British Arms industry, and support the call for heavier taxes on the rich.
And for the love of God, write a strongly worded letter to the Cadburys corporation!!