The way Boney portrays Dwarves, they don't jump straight to slaughter and they won't jump to genocide over trade caravans. They ask for compensation first, and failing that they declare a grudge and set out to deal with said grudge. They aren't the unreasonable war mongers of canon, and even canon didn't portray them as genocide happy warriors until the War of Vengenace novel. It doesn't "make sense" that Dwarfs would jump to genocide, even to settle scores, because that's just not how they do things in DL. There can be a couple bad actors sure, but in that case the High King would definitely punish them and wouldn't sanction such activities. The Dwarfs have a semi-reasonable society that's survived for thousands of years, 2000 of which involved an alliance with the Elves, and jumping to genocide is not a reasonable recourse for how they are presented in DL as a polity.