I actually think it makes a lot of sense, especially if you look at the other companies they own (Dallas Airmotive, for example). Take a look at the Ontic website.
Signature FBOs tend to be lousy because of their business model-- acquire monopoly position at busy air carrier hubs. Those are by nature expensive, and since they have no competition, they don't have much incentive to provide good service. In places where Signature FBOs have competition, they're usually okay.
In Twin Commander's case, they have somewhat of an incentive to keep parts prices within reason, since they want the fleet to continue to fly and rack up hours, and parts usage. If they over-price the parts, or reduce the support, many operators will switch to something else. And it seems like more and more Twin Commanders are in utility roles rather than corporate/private usage, so they are going to be fairly price sensitive.