No no no.
"Rossi asked for a less powerful engine, that can get the power down through the corners and help with exit speed????"
Rossi has asked for smoother power deliver and they've delivered a new engine and electronics to achieve that.
"Why pay to get the greatest rider of his generation"
That depends on how you define his generation. If you're excluding the other aliens, you'd say he's the only great rider of his generation. If you're including them, you'd say he was probably the third greatest. Second at best.
"then ignore his feed back,and just give him what you want to make anyway??"
I know Rossi said they've ignored him when he spat the dummy at the start of the year, but that's just how he plays the media manipulation game. Preziosi came out perplexed at the comments (it's on motogp.com).
You cannot say that Ducati haven't bent over backwards for Rossi. New parts galore. New frames, new engines, new parts everywhere. When Rossi is now asked what he needs, he says he's out of ideas. Ducati have tried to make the changes he suggested, but they haven't worked.
You can argue they're incompetent, but it's not fair to say they've ignored him.