Obviously, there is a certain anti - Zep faction here, as witnessed by the sarcastic nature of the op.
Who knows why Plant is uninterested. It may be his voice, but I am sure they could do something to pull off the job. He may also be interested in the new direction his career has taken, one that has him making FRESH music.
One thing I have always applauded Zeppelin for is how they have used the name of the band. They ended the band when Bonham died. They knew how key he was to the sound. When Plant and Page decided to make some new music, they billed the tour as what it was, Page and Plant. They could make a boatload of cash touring under the Zep name, and yet the haven't after nearly 30 years. I would hope Page has the sense to not ruin that name by touring as Zep with "some other guy" on vocals.