But I'm not sure that frozen bodies in a fridge is more disgusting than rotting corpses in a casket.

Right, but people are used to rotting corpses in a casket. So they don't think about that when they think burial. They think of pleasant-looking graveyard with pretty flowers.It is precisely the uncommon nature of cryonics that causes one to think about what it looks like.

The main thing I don't understand is what incentive does anyone have to keep me plugged in after I passed away?

Well, most of the people running cryonics organizations are themselves signed up. They want to keep people preserved so that they will get preserved. Moreover, friends and family should want to keep you preserved so that they can see you again one day.

Lets say there's an earthquake or a tornado in the area, it would be easy enough to say that this was the reason why the bodies were lost. It would always make more sense to people to save the living rather than the dead.

Sure. Given that choice that is the correct course of action. I would disagree with calling the cryonicly preserved people "dead" since that implies ontological and moral claims. But, in general, they are less likely to end up functioning than the people who are currently alive in the traditional sense. In that regard this isn't any different than deciding that when one has a choice between rescuing an aging, terminally ill cancer patient, and rescuing the healthy 18 year old, you rescue the 18 year old. But this isn't an argument against cryonics except in so far as it is an example of one of many situations where the cryonic preservation might be terminated. But there are a lot of those. That's one major reason even most cryonics proponents don't estimate very high chances of any given cryonically preserved individual being successfully revived.