I remember reading an essay once that explored the difference between "having diabetes" and "being a diabetic".
There's a wide and wavy line there between being consumed by (and unnecessarily limited by) the idea of "being a diabetic" and just "having diabetes".
If diabetes gets so big that you can't see anything else but a big red D in front of your eyes morning, noon and night, perhaps it's time to re-evaluate?
On the other hand, if you try to push "having diabetes" so far down your list of priorities that you're testing three times per month, racking up a stack of double-digit A1C results and have to look at your feet to see if they're touching the ground or not, that's not good either!!!
As AR23 pointed out so eloquently, if you're actually USING the data to help manage your diabetes, then is there really such a thing as "too much testing"? when I had my first few bad hypos, I tested every five or ten minutes -- six or seven times in an hour -- just to reassure myself that 1) I was coming up; 2) I wasn't crashing again (i.e. no, I had not mixed up my Novolog and my Lantus); and 3) I didn't need to call for help. Was that "excessive" testing? For a seasoned person, sure. For me? No. It bought me the data and the reassurance I needed in that moment. Would I test that much if I had another hypo this evening? Probably not because I wouldn't need the data. I understand now how to treat a hypo and how/when to re-test to get the information I need to be well.
I think diabetic kids and their parents get into power struggles around testing because of different life experiences. As young people, we tend to think of ourselves as invincible. After a few HARD knocks (e.g. car wreck while inattentive, broken arm while skateboarding, death of a close friend via drunk driving, death of a beloved middle-aged smoker relative via lung cancer, rape of a dear-to-us co-worker on her late-night solo run, etc.) we tend to be more protective, more AWARE of our own mortality and the mortality of everyone we love.
Of course a parent wants to know the exact value of their beloved T1 child's BG every second of every day. They also want to know who they're with, what they're doing, the intentions of everyone they might encounter, etc. As the saying goes, when you bring a child into the world, you start "wearing your heart outside your body" -- the death or serious injury of that beloved child will HURT you. Badly. Part of parenting is, of course, learning to manage that concern and anxiety such that you don't smother the child but at the same time don't recklessly ignore their well-being.
Whether it's our own diabetes or the diabetes of someone we love, there will always be dynamic tension -- and disagreements -- about what is "too much" and what is "not enough". That's the nature of the beast.