Obito has a character in place and to make us believe that it was him to the very last minute, he stayed in character. It makes sense seeing as how extremely deep cover agents or people who are really imitating others have to act, speak and think like them. If he broke character, he might have broken it in front of the others at a sooner point. I think Kishi had him say this to keep us fooled.
I also think that Obito did originally plan to revive Madara as Madara would help to finish the plan. The thing is, is that he didn't want Madara to be the jinchuuriki of the Juubi. But once he had kabuto, I think Obito used it to his advantage to seal the Juubi as supposedly Madara couldn't as an edo (even though Minato managed the Kyuubi).
Also, at the time of these quotes, Obito still had Madara's seal on him, which may have effected his personality and thought patterns, it wasn't until Kakashi stabbed Obito in the chest that Obito was actually able to defy Madara, but that was well after Madara was revived as an edo.