I have had a lot of email discussions with friends and family about the value of Facebook. Many complain that it is difficult to manage and one must do a lot of tweaking to get it to filter the barrage of unrelated comments that are posted.
One suggestion was to reduce the number of friends. That probably defeats the concept of having all of your friends accessible in one location. I don't like this option.
I personally use lists. Lists on Facebook are basically filters. You give the list a name and then assign friends to them. So, if I have one called coworkers and only include people who work with me in the list I can click on coworkers and show only those conversations. You can create numerous lists and use them to filter what you see.
One could create a Facebook group that would be targeted to a particular topic but I have had only a little success with that. Many businesses use Facebook groups for fans of their products and in effect get free advertising.
The process that seems to have evolved among a few friends involves migrating an interesting topic that pops up to email or Facebook messaging where it can be continued in more length.
In short, it takes some work to configure Facebook to be more useful. Some think it is not worth the effort. I will probably stay with Facebook because it is the only single place where all of my friends and family can be reached. Since some are discouraged by the techie aspect of tweaking it to be more useful we will probably lose one or two Facebook Friends but overall I find it more useful than annoying.