Sure. But I think it's analogous to the days of patent medicines. Coca-Cola really did contain cocaine at some point; opium and heroin were also popular ingredients. [1] Did the people making those medicines intentionally set out to sell dangerously addictive substances? I doubt it. They just tried to make their sales graphs go up and to the right, experimenting and copying what worked in other patent medicines.

The only reason things changed is that there was a national outcry. People came to recognize the dangers of addiction. When Coca Cola was created in 1885, it was made from coca leaves and kola nuts. By 1891, they cut the coca content by 90%. They cut it again in 1904, and by 1922 went entirely without. [1, 2] And it wasn't until 1983 that they offered a version without the other addictive stimulant. [3]

I think we're starting to see the beginnings of a similar outcry today. I hope we'll see more of it. But if we want it to have an effect, it will have to happen at a societal level (e.g., the threat of regulation) and an individual level (with more people refusing digital time-sucks like Facebook and Candy Crush). I also think it needs to happen at an interpersonal one; people working on addictive digital products should face social questions, just like somebody making cigarettes would. Because as you say, many of the individuals creating things like Facebook just aren't thinking about these broader issues.

[1] See, e.g. https://io9.gizmodo.com/how-todays-illegal-drugs-were-market...

[2] https://www.snopes.com/cokelore/cocaine.asp

[3] https://en.wikipedia.org/wiki/Caffeine-Free_Coca-Cola