Maxims abound in the self-help/productivity game. They're peddled primarily by people who reword or, more optimistically, repurpose existing rules generated by others for a new context. Whether you're using the maxim "single-task", "say no", "do less", you are using a rule that has been created by another, hopefully from a process that involved seeking an understanding of some problem. You may gain much by following the maxim but you haven't gained the understanding that was gained leading to its formation.
Maxims seem to have the most power when actively wielded (usually when they're first discovered), with their power diminishing over time. This isn't so much about the consciousness of the maxim so much as being able to get away with delaying tasks that don't fit into them. Most tasks can't be delayed indefinitely, and then things break down when the incompatible task hits the rule made rigid by not having sufficient understanding to seek compatibility (or, perhaps, to specifically not seek compatibility).
The general response to that is that the maxim is a guideline (or perhaps a mantra), not a rule. That one is supposed to keep it in mind, rather than rigidly follow it. Consider it as a factor in every decision. But it matters little — without the understanding, you are left powerless to deal with incompatibility.
There seem to be three levels of understanding of an activity, whether about how you work as a person or about how one develops software. In the first level, you follow the rules others give you. In the second level, you try to understand how the rule works, why the rule works, what other rules exist out there as competition or as allies, and begin to be able to create your own rules. In the third level, you no longer think in terms of rules, but rather just act appropriately based on the full available context — making decisions from your "gut".
(Somewhat separately, I discovered or possibly rediscovered Shu-ha-ri, which has the same levels, but may or may not suggest these same meaning for these levels depending on which article you read about it. The current Wikipedia page, as linked, has the same meanings.)
This leads us to an interesting problem — someone who has achieved a high level of understanding about an activity can appear to those with a lower level of understanding about that activity to be acting incorrectly. They aren't following the rules that others have heard of, and they haven't followed the rules that observer individuals may have made for themselves.
Where your success speaks for itself, say in some martial arts (Bruce Lee's Jeet Kune Do being perhaps the most apt example) or in self-development, this may not be a problem, or may even gain you respect. However, in business and many other communal/organisational activities, even continual success doesn't confer any sort of pass on describing why things should go as you say.
Since you're not using rules from a particular well-known practise, you can't refer to any sort of "definitive" sources. You also can't be sure what rules your audience has made themselves. In this case, you have to teach your new set of rules to others, possibly helping some to unlearn contrary rules, layer by layer until you reach your suggested outcome.
Does one need to work from first principles every time? This is a very time-consuming and energy-sapping undertaking. Does one need to work from first principles every time someone new is brought in? Should one make that assumption that someone you've convinced from first principles before will remember the argument from first principles, or still agree with it?
I guess this is an activity that requires mastering itself, and there's no good quick answer to it either.