"core idea of" is a perfectly valid and usable part of a sentence in written English.
For example, "The core idea of the article was to discuss the importance of education."
The core idea of this is to maximise customer value while minimising waste.
"Rest assured that whatever the modifications, the core idea of each plan will be preserved.
This was his core idea of politics: great speeches, historic figures, a common purpose.
The core idea of P2PU is putting people together around these open courses".
It all sounds like a lot of work, which seems antithetical to the core idea of watching television.
That's the core idea of the site," said writer and professor Clay Shirky, who studies social networks.
And while the core idea of this agreement is a good one, the execution plainly is not.
It has to do with the core idea of the opera: Saariaho's experience of the pain and beauty of birth.
They sign up to the core idea of consumer freedom and individuality, but in reality they are deeply tribal, in their tastes, clothes and behaviours.
But not, perhaps, enough The core idea of co-operatives is that the people involved in a business are the best people to guide and own it.
The visitor gets to grasp the core idea of special relativity -- that time and space are not absolutes but change with the viewpoint of the observer.
