I think the challenge is always in the details and not in companies trying to overparent their users. When I post something to LinkedIn, there is some tacit expectation that I want good opportunities to come my way, and I don’t want lots of spammy ones. And I will blame LinkedIn (rather than the Internet writ large) if I get overwhelmed with nonsense. Not everyone feels this way, but most do. So it isn’t just about business model.
But even if it is just about business model — that was kind of my point. If LinkedIn went to the effort of soliciting the information from the user for the user’s benefit and for LinkedIn’s business value, why should other companies benefit from that gain without either having explicit consent from the user or from LinkedIn to get business value.
It is a similar question to if I post something on medium, can anyone just scrape it and repost.
In terms of “parenting”, I have always liked that Craigslist works hard to defeat spam if I post to them, even if one could argue they should let my listings flow further. One think I appreciate about how they do this is there is a checkbox for “ok for others to contact you about other services, products or commercial interests” that is unselected by default. So by submitting on Craigslist you make it clear that you are not open to spam. Other sites should have things like this such as “ok for my information to be ingested and saved elsewhere beyond search engines for marketing and profiling purposes or republishing or whatever” so we can be explicit about intent