Short answer: Yes, it bothers me a lot.

Long answer: Being incompetent is not the issue as others already said. The issue is when people fail to realize their incompetency and even worse do not want to do anything about it.

"They didn't even read my email"

One of my biggest pet peeves at work. I am always amazed to see that people don't read important emails and will then call you asking for the same. Heck, they even get upset and when I ask "Did you read the email?", they will be like "uh oh. i didn't get any email.". i mean seriously, WTF. RTF(E)