Not "just as easily"--frequently "more easily". The reasons for not doing so are varied. One reason is that it increases engagement and reach because it becomes easier to respond to--and retweet--individual pieces of information or individual thoughts as the thread develops and you get more bits of the thread popping up on feeds over a long time. Another reason is that it also enables alteration of the original plan based on feedback given as the thread develops. In Abramson's case I suspect it's largely because this increases his reach and increases exposure for both old and new threads--and because this is how it's done on this particular platform.
FYI, Abramson is a borderline conspiracy nut. Smart guy, but goes on massive, poorly-sourced rants.