Why limit to online casinos? WMS Gaming creates tons of slot and video lottery terminals, wouldn't it be just as unethical to work there than on online casinos?
Exactly. Online casinos are just the tip of the iceberg here. Unbelievably large sums of money and grief are lost and created respectively in real world lotteries and casinos which nowadays are almost entirely computerized - thus made up by developers working in tech companies.
I do think that online casinos may get a worse reputation when it comes to those in the US because online gambling is illegal so these companies that offer it are set up outside of the US jurisdiction. Who knows what they will pay out or if they ever do pay out. Casinos in the US are bound by the governing body of the state they are located in to have certain payouts when it comes to machines. Online gambling doesn't necessarily have that.