You are dead set stupid - there's also the issue of the importance of runs... while runs are runs, go through Watson's career - for the most part he has scored them either in a two year period when he was actually good, or in flat conditions when everyone else scores or the series is already won...
Against a poor Indian attack when even Marsh could score runs, Watson has been demonstrably shit - while you might be right that there's no obvious replacement in Australia domestic cricket, surely pretty much anyone batting in the top order in domestic would do no worse (actually I think that's been proven with the two Marshes and Burns).
You can defend him all you like, but any serious look at Watson leaves a lot to be desired, but good that he has fan-boys like you - even locky has changed his tune