Naming conventions
In physics, terms like "work", "power", "force", and the like have very precisely defined meanings. However these words also have meanings in everyday life which do not coincide with their physical definitions. This is probably unfortunate, in that it results in words having two meanings. Thus while "work" in physics entails moving a "force" through a distance, ordinary everyday human work is not entirely simply a matter of moving force through distance. While a labourer shovelling earth may be said to be performing physical work, it is not entirely clear that a physicist writing equations, or imagining equations, or just gazing absently into space, is performing "work".
But the alternative to adopting words from common currency is to pick words that are otherwise meaningless. The Greek word "ergon" might have been used in place of "work". But since nobody knows what "ergon" means, unless they have studied Greek, this will mean that "ergon" will appear entirely meaningless at the outset, whereas the word "work" already comes with a meaning which is similar to, if not exactly the same as, its physical meaning.
The term "idleness" started life as "efficiency." However in physics, the "efficiency" of a motor refers to the fraction of the energy input to the motor which is converted into physical "work". In short, it already has a meaning. The term "idleness" is far closer to to what is actually meant: the fraction of its time that some creature is idle or inactive.
But of course "idleness" already has a meaning in everyday life, and one which usually carries overtones of disapproval in a society in which "keeping busy", and "doing things" is usually regarded as preferrable to "doing nothing". In this sense, "idleness" is a bad name.
However, since the entire thrust of this idea is that a state of idleness is preferrable to a state of busyness, in opposition to contemporary mores, the adoption of the term "idleness" is quite appropriate, because this idea challenges conventional wisdom.
The same applies to the naming of the idea as "Idle Theory". An idle theory is, in ordinary usage, an idea that is entirely hypothetical and valueless. When writers say that some idea is "no idle theory", they mean that it is substantive and valuable.
Now Idle Theory is in fact both largely hypothetical, and also largely valueless. That is, it is not an idea that has empirical foundations. Nor is it an idea which has any current use. Therefore calling it "Idle Theory" is quite appropriate, even if it may one day turn out to have practical value.
And again, since "idle theory", along with "idleness", has connotations of social disapproval, and Idle Theory is in conflict with conventional wisdom, to adopt this name is to challenge conventional wisdom, and to accept disapproval.
In these respects, Idle Theory follows the lead of The Rolling Stones, The Beatles, The Animals, The Kinks, and the like. These bands did not give themselves good names. Indeed, since their values were opposed in some degree to conventional values, it was entirely appropriate for them to give themselves 'bad' names. And it did them no harm. And it perhaps served to revalue rolling stones, beetles, animals, and kinkiness.
Idle Theory is a subversive idea, and it is appropriate to give it a subversive name. It is subversive because it sets out to undermine to a whole raft of conventional wisdom. There is nothing wrong with trying to do this: conventional wisdom is there to be criticised.
If there is anything unfortunate about the use of "idleness" and "idle theory", it is perhaps that they suggest that the goal of life is to do nothing. This is not quite what is actually meant. Rather it is to suggest that the goal of life is to be able to do nothing, and that to be able to do nothing is to be able to do anything.