The main difference between forums and social networks is anonymity, and that the forum is written-only.
By definition, a forum is a platform used to bring in discussions, sharing ideas, or anything of a certain category, whether offline or online which means privacy/anonymity is just a feature that we took and implemented according to our needs.
Bitcointalk is special and for no reason I love the old school theme than the fancy UI of other forums and also forums that replicated bitcointalk tweaked some feature than has been requested by the community more often but still people here love to hangout and participate in the discussions than anywhere, probably because the active members with actual knowledge is more than anywhere else and we can't deny the participation of signature campaigns too.
It seems like you have a different view than others on this.
I completely agree that forums are platforms used to hold discussions, share ideas or certain topics, both offline and online. Privacy and anonymity are usually features that can be used in forums, depending on the needs and implementation of the platform.
Interesting that you like the old school theme on Bitcointalk over the more modern interfaces of other forums. Everyone has different preferences, and there is no right or wrong reason for choosing a preferred theme. Maybe you feel more comfortable and connected with the community on Bitcointalk because the members are active and have up-to-date knowledge.
Regarding the impact of the mixer ban on the forum, it sounds like you want to consider how the ban affects the forum. Have there been changes in member participation or changed discussion topics? This could be an interesting topic to explore further.