It's mostly RP reasons. I've always found Sylla a bit difficult to write for, because she's so angry and unlikable. But she connected with the Goti during Greener is the Grass (to my surprise, actually), and letting her stay with them for a few months seems like important character development. Also, if I spend the DMC, then (a) it shows that she actually did grow up a bit while she was there and (b) it gives her enough cash to get a full set of Goti-themed upgrades for her stuff. In other words, it's a very good opportunity not to have her jump into another adventure.