I think a big part of the shift of interactions over the last 5 - 10 years is the communication platform (Facebook, in this case) bringing in new users who had zero experience debating in a text-only format. It’s probably inevitable, unless the platform tries to educate and heavily police new users on what proper behavior is.
Facebook was incentivized to grow as fast as possible. Comments and discussion was one of many vectors for growing; photos, news, and silly images was just as important. The quality of all that wasn’t as important as the content coming from people you know and trust.
Contrast that with a community like HN, where quality of comments and content is much more important, since you have little to no trust for almost all people submitting content.
Facebook was incentivized to grow as fast as possible. Comments and discussion was one of many vectors for growing; photos, news, and silly images was just as important. The quality of all that wasn’t as important as the content coming from people you know and trust.
Contrast that with a community like HN, where quality of comments and content is much more important, since you have little to no trust for almost all people submitting content.