Because those are all pretty new phenomena, so the literature and treatment culture around them are scarce. Whereas drug and alcohol rehab has been effectively

Because those are all pretty new phenomena, so the literature and treatment culture around them are scarce. Whereas drug and alcohol rehab has been effectively an industry for decades (or even centuries - the Salvation Army was founded in 1865...). Also, as others have said, the societal impact of substance abuse are often much more visible, directly measurable, and immediately felt.