This one certainly does seem to require a bit more direct knowledge of WP to interpret than I have compared to some of the others. It sounds like the strongest argument against it that is that he previously has been against plugins being listed in the default page and that he doesn't seem particularly open to having published guidelines for what merits being there by default, which means that what belongs there essentially is left up to whatever he decides with no one else having a clear picture of it.
In a vacuum, probably not a huge deal, and maybe for people who actually use WP the idea that this is basically something up to a judgment call makes sense. At least from my outside perspective, it sounds a bit like what's on the default page is basically being left up to the whim of the CEO without any real concrete explanation, which would be mildly concerning even if the CEO wasn't someone who's been making the news a lot the past couple years from getting into pissing matches with competitors, causing 8.4% of his employees to take a blanket offer to leave: https://www.sfgate.com/tech/article/automattic-workers-quit-...