That’s just how it is these days. Companies are all getting their social media teams to do this because it generates attention.

I don't think this is a top-down deliberate strategy. As evidence, if you load the thread today, a bunch of comments are gone, including all but the first two comments from the @Raspberry_Pi account. Most likely an adult showed up, realized it was creating horrible publicity, and deleted a bunch of stuff.

Though... looking at https://www.buzzfeednews.com/article/chrisstokelwalker/raspb... , it looks like one of the founders is not necessarily much better: called the complainer a "concern troll" and refused to admit any wrongdoing or responsibility as an organization.

An organization has a responsibility to never hire anyone who's ever been involved in an organisation a few people on a tiny social network dislike?

No, the decision to hire the guy seems reasonable or at least defensible. The thing the founder would ideally have addressed is that the behavior of the social media manager, in responding to the posters' complaints (about the hiring decision, and then about the behavior), was excessively dismissive, escalatory, and generally inappropriate.