Pot shouldn't have been criminalised either, because it was long registered as an effective medicine from Victorian times and earlier. From what I've read its prohibition was a means of repression of certain 'undesirable' groups (particularly racial groups) in which social use was popular. That said, the effects of its prohibition are nothing compared to the creation of hugely rich and powerful criminal groups from the prohibition of Cocaine and Alcohol.
Prohibition of gambling wouldn't have the same effect as alcohol and cocaine prohibition, because the sites will remain available, but access to them will be restricted. The odd thing is that this approach is anti-protectionist - instead of protecting US businesses, it further reduces the opportunities for US businesses to compete in an established global marketplace.
When will the US (and the UK, which thankfully is just stopping companies offering incentives to gamble with them rather than banning
online poker) recognise that prohibition is a blunt and flawed instrument, capable of great harm? Rather than offering counselling and education programs, the decision is made to criminalise and prosecute, putting more people in over-crowded prisons, reducing the workforce, reducing tax revenues, and giving more power to criminal (or in this case at least non-US and non-tax-paying) groups. Almost none of the sites will disappear if US players cannot play there since they have players worldwide, so blocking access to such sites would require a censorship effort on a scale of Chinas much-criticised efforts.
I'm sure all of the poster in CardsChat support groups trying to reduce the incidence of problem gambling and gambling addiction, so long as they take a measured 'harm reduction' approach, rather than an ignorant and short-sighted 'we can eliminate harm' stance. Part of the solution is perhaps to support those initiatives, in support of sites adopting standards of conduct to minimise problem gambling, and in assisting compulsive gamblers in getting help, so that alternatives to such crude and mis-guided efforts are highlighted.
For myself, I hope that similar legislation doesn't crop up in the UK, or that it doesn't get anywhere.