The title choice between Return Of The Jedi and Revenge Of The Jedi did involve some considerable back forth between the two titles.
It was felt the 'Return' title was a bit weak and wishy washy. It also recalled the recent film 'The Return Of The Pink Panther' and Fox were worried about being mocked for that connotation. The marketing dept had also carried out 324 telephone interviews in which participants were asked to choose between 'Return of the hero' and 'Revenge of the hero', the 'Revenge' title overwhelmingly was thought to be more exciting.
The other issue was that Revenge posters and a trailer were in public domain, and that Kenner had already begun production of Revenge branded toys (estimated that the title change cost Kenner $250,000).
Lucas flip flopping between the two titles certainly must have p***ed a few people off and wasted money, but in the end as history says he decided that 'Revenge' was not a noble Jedi trait.