Anyone who has worked in PCA circles for a while and understands the "vibe" of the culturalist wing can understand why Chappell would consider those names as scandalizers. The outliers are actually Byrd and Higgins because culturalists generally blame the conservatives as if women are "forced" into their situation.
You have to remember that many culturalists were upset by the actions in the FV controversy. It's generally considered bad form by many to express any more than a furrowed brow at things like paedocommunion or Side B. You don't agree with it, but you want a "big tent" and to be "Missional".
So, when conservatives make noise inside the denomination beyond the furrowed brow, they are considered toxic and scandalizing.
Notice, however, that Jemar Tisby is not on that list because I think many believe that it's the fault of conservatives that he is where he is.
It's a bit of an exaggerated logic that I'm explaining but it's not far from the vibe of a substantial wing of the PCA. Let's just put it this way - if it was up to that wing, the PCA would be full-blown Sidde B accepting.