While not a disaster, I would admittedly be mad if my flight's pilot attempted three landings at DCA in bad turbulence despite an easy diversion option at a major airport nearby.

At some point, the pilot should be more sensitive to the mental welfare of the passengers, even if there's a good (but not excellent) chance the next landing attempt will work. I'd understand two go-arounds, but after that, I'd be calling ops and asking why I can't land at IAD or BWI, both of which have Delta service.