User blog comment:Miskos3/Fairy Tail Chapter 488: The Two of Us, Always, Review/@comment-5426822-20160606213319/@comment-9595671-20160607063221

I think the reason Mest decision seems bad is because Brandish seemed to be nearing a Heel-Face turn from what I've been seeing. With what he did said, it's likely going to take much longer now for them to gain her as a full ally.

Though I can kinda see the whole Dragon Slayer thing you mentioned, but maybe more along the lines of being KOd as Acnologia nears, making his threat larger as the only Wizards who can properly fight him at any terms won't be available to help when he finally arrives.