"Responsibility" is a very important thing as is a fair and reasonable approach to everything, hence ensuring that as many (& if possible all) requirements are covered.
The term "decaying" can be rather "confusing" to some, as when I have used this term in conversations about the votes us witnesses get from Steemians having a fixed term of validity. i.e. 365 days (12 months) from the date that the vote is cast, some people do pop the question "What exactly do you mean by decaying?".
Most often than not, it is "misunderstood" to mean that each day the vote goes down by a certain proportional value, i.e. -1/365 * total vote MV.
Which isn't the case for this topic.
However, in your example I would actually add how the term "decaying" with this interpretation could be applied and defined as such. Because it would be a daily calculation and constantly changing in its % (proportional) value.
Personally I like the proposal, it makes sense for many reasons, including the fact that everything needs to be a two way street in order for progress to be achieved.
Thumbs up!