If Obito uses Rinne Tensei to revive Madara does this mean Neji and Inoichi and Shikaku will be revived and all the other fodder shinobi who have fallen during this war?
Nagato died due to stress, Obito would die because his body can't handle the enormous strain Rinne Tensei makes use of. Note that Nagato didn't bring everyone back to life (Jiraiya, Yahiko, etc.) There are specific conditions for it that Kishi has been deliberately vague about. I think we can all admit that it'd be lame if Neiji magically lived.