I hate

The phrase "Treat the disease, not the symptoms". It's a reasonable enough statement, but is almost never used reasonably. Problems with it:

1. It's not a binary option, doing both is entirely possible and often necessary.
   
2. Doctors treat symptoms all the time - they're usually the things that are going to kill you.
   
3. Almost everybody who uses the phrase doesn't give a shit about the actual problem, they just want to feel smarter than anybody actually dealing with it.
   
   

Last time I had it thrown at me was in a conversation about a scheme I work with that gives interview training to unemployed/homeless men. One smug asshole pipes up with "That's just treating the symptoms, it's not addressing the disease". And I looked at him and thought "You don't give a shit about the actual problem, you contribute nothing to it in any way, but you feel really superior for saying that.".

Actually, I thought that later. What I thought at the time was "Die, you worthless piece of shit."