Are there any sayings that drive you up a wall?

That is exactly what it is. Don't spend your energy on something you can't change.

Sometimes that is a good approach. For example, trying to get a single parent who is illiterate, mentally ill, or sick to help their child with homework in the evening is wasting time. It is an approach that won't work. I can see telling someone who keeps pounding that idea, "It is what it is."

Other times that phrase is just used as an excuse to shut down all ideas.

In my opinion, that phrase can be appropriate. It is all in how it is used and what follows next. "It is what it is. What other direction can we take to fix this."

 

Yeah. That is a battle not worth fighting. I understand you pick your battles wisely. I have only heard the words used when a kid flips out, cusses, destroys stuff, hits, and throws stuff.
I think you can teach kids not to do those things IF you are consistent and allowed to have a basic natural consequence to it. Like clean it up and work to pay for what you destroyed. Every single time....
This is not a natural consequence, but I have noticed it works when a parent follows through: Find something they really enjoy like a game or activity. They can do the activity each day they do not throw, hit, spit, etc. stuff.
Unfortunately, parents of kids like this seldom follow through because the kid throws the fit at home, they want it to stop, and give the kid their own way.
You can teach the kid school is not the same as home and they will not get their own way by throwing fits. As long as you are able to give calm, consistent, consequences for most kids. Instead of making excuses like : It is what it is......

 

"It's all for the children".