This. It's also easier to strike in without losing position, and Traditional Scarfhold (Hon Kesa Gatame) is a bit of a transitional dead-end and has fewer submissions compared to Broken Scarfhold (my favorite is the reverse triangle from here, both as a submission and a position to isolate and attack the far arm, strikes to the belly (and to the groin on t3h streetz) are very viable from here too). As a pin Traditional Scarfhold is fine and so is useful in Judo and wrestling, but BJJ and MMA fights can't be won with a pin so it's even less useful.
Bolded part is the key here. You have a couple of subs, or you can pin (nearly pointless in MMA if you can't simultaneously strike), and that's it. Hard to transition out of it without creating an opportunity for your opponent to escape.