Incessantness
The Century Dictionary and Cyclopedia
noun.
The character of being incessant.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
the quality of something that continues without end or interruption
Word Usage
"If by "incessant whining" you mean "whining in a manner reminiscent of incessantness" then, OK, I agree."
Hypernym
Words that are more generic or abstract
endlessness