so, hypothetically, I am the boss. I used to be technical; but that was long time ago. I am responsible to the users for the performance of the application (ERP, Medical Records; Inventory - whatever) or client-facing website. And it is slow! So, I ask DBA to troubleshoot it. What is the bottleneck. Is it a single (or small number) query? Or is it some query that - while reasonable - is invoked in a loop and has overhead that slows down the system? Or maybe it isn't on the database layer - the data get processed in the application layer? Wait - it maybe even in the browser? We are running SPA, after all - and if it takes 5 seconds to build a grid, it doesn't matter that the response comes in milliseconds.
Now, 3 days later DBA comes back and tells me that she found several very inefficient queries - and we should tune them, and they will run in half the time. Nervous, I am asking, how fast do they run now. 200-300ms, she replies; and if we change the structure a little - it can run 10 times faster. I summon my inner Borat and say "That's nice!". Is that the bottleneck? - No, not really, just very inefficient query.
But what's the bottleneck, I repeat? In response I get geeky mambo-jumbo about instance parameters; and index scanning vs. index seeking; and sharding; and TempDB parameters. Fortunately, client manager calls me to say that Azure AD is down - so I can send DBA to another class she was nagging me for months.
That is why I don't care about query tuning. Every IT area has their pet peeves (Developers; Networking). Show me how yours affects business - and I sign off on all conferences you want to go!