The phrase "a waste of focus" is correct and usable in written English.
It can be used to describe a situation or activity that diverts attention from more important tasks or goals.
Example: "Spending hours on social media can often feel like a waste of focus when there are deadlines approaching."
Alternatives: "a distraction from priorities" or "a misallocation of attention."
So the lesson is, knowing such things doesn't really have a use and it's a waste of time to focus on them, that time could be much better spent developing oneself.
He considered some of the daily political give and take a waste of time and focused instead on the fight for the poor and weak, even offering to mediate in Sudan's troubled Darfur region.
Within the research education working group there was no consensus regarding the effect of such lack of formalisation: does this lead to a waste of time and loss of focus, or is this academic freedom or avoidance of unnecessary bureaucracy?
This is "What if Derrick Rose Were Healthy during the 2012 Playoffs": "From my base in the moon, I witness many realities, most of them radically different from the world you know, so it is a tad bit of a waste of my cosmic awareness to focus on such a mundane question.
Methodology wars are a waste of time and put our focus exactly where it shouldn't be -- on ourselves.
"It's a waste of time, money, energy and focus and people should be looking for [Lisa]." While authorities have declined to discuss many aspects of the case, they did spend a significant amount of time conducting an aggressive search of Bradley and Irwin's house.
A girl's education is also often seen as a waste of valuable resources, with families focusing on educating boys.
Some educators contend that the environmental focus is a waste of taxpayers' money and a distraction for schools at a time when many students are ill-prepared for college and struggling to meet minimum standards on math and reading tests.
Any distraction from that focus is a waste of bits and bytes.
He goes on to call Trump's tweets "angry" and "childish" and a waste of time when he should be focusing on more important national issues.
