"I don't like it"
"I don't understand it"
Those are the only responses your new idea can possibly generate from many around you if your new idea is actually a great idea, something ownable, something you can build work around.
The popular, obvious, guaranteed ideas have definitely been taken, or are so small that they're not really worth your blood and tears.
That means if the new title of your book is instantly understood by all, it's generic or descriptive, not something that people will associate with you as a creator or as someone who brings us new insight.
That means if your app does something so predictable that everyone is sure it's going to work, you're not making a big enough leap.
And that means that if your political idea is so palatable that everyone is going to vote for it immediately, it's not going to change anything.
"I'll ask around the office," is shorthand for, "no. Make it more boring. Banal. And less likely to succeed, please."