Most people tend to use “as well as” when they are speaking about or writing about a list of things, regardless of the importance of each item. For example: “I keep quarters, a bottle of water, as well as a box of tissues in my car.”
To me, this says that the quarters and water have been added to the box of tissues that is already there. This is not the same as “I keep quarters and a bottle of water in my car, and a box of tissues as well.” In this construction, the tissues are the afterthought.
Which is the afterthought in each of these sentences? “There were many members of activist organizations at the meeting, as well as unaffiliated people.” Or “There were many members of activist organizations at the meeting, and unaffiliated people as well.”
Does it really make a difference? My pedantic self says it does. It is a matter of where to place the emphasis.