If Rooney ever signed, the media wouldn't start caring about Everton, they'd stop caring about Wayne Rooney.
Take away all the sentiment over Rooney for a moment. And all that's left is a rapidly declining player who would come nowhere near to justifying the huge wages he'd need, and struggle to nail down a position in our first team. With the very real danger that he'd block the progress of new academy graduates.
Lets look to the future, not the past.
...the point I made is that he could have more of a strategic off field impact. I'm not advocating we should acquire him, I'm just saying that the club might see him as raising our profile in support of 'Project Everton'. It might be that he would be a cost effective signing. It's an angle the club might consider although I doubt it will happen.