Hi!
makes sense to explicitly record the absence of a value. For example, one might want to say that a politician is not a member of any party, but one would not add this information to every human.
One common example is George Washington (Q23). While most of the US presidents has been members of some political party, George Washington did not like the idea of the parties and refused to join one. Thus, https://www.wikidata.org/wiki/Q23#P102 features "no value".
Also, I don't think that no-value statements make much sense in qualifiers, besides maybe serving as "documentation" for other users who
I'm just about to write a long email about it :)