They certainly didn't get so addictive by chance, but not quite by design either. It's a kind of evolution, where some machines suceeed and some fail, with succ

They certainly didn't get so addictive by chance, but not quite by design either. It's a kind of evolution, where some machines suceeed and some fail, with successful techniques carrying through to newer machines, eventually leading to hyper-optimised money making devices. Whilst not disputed that this leads to ethically dubious profits, I can see how it allows the manfuacturers a certain plausible deniability as to their intentions.