I wholeheartedly agree with the first part of this statement. I've been called a "hacker" plenty of times, and once that happens, I say it's fair to call yourself one, but not before.
No one would have ever called me a software developer. There are many kinds of hackers, and not all of them are coders or developers.
I whole heartedly disagree with the first part of your statement. I considered me to be a hacker long time before I got called 'hacker' by my peers and clients.
As I already wrote, I do tell some people that I am a hacker. Most of the times this a result of the question: 'So you are a hacker?' After I explained what I do.
Saying you are only a hacker if your peers call you that just raises the mystery around the term hacker.
Last part of your statement I fully agree to. Hacking at first has nothing to do with software or hardware. For me it is using stuff in a way that is was not intent to be used. Being in Africa right now, I see a lot of clever hacks, where people use for example climate control devices to get more or less clean water, reusing garbage to build new stuff and so on.
I am more concerned about the phrase 'expert'. This is imo something you can not label yourself. And even if.. it sounds always kind of strange to me.
But seriously, it seems "hacker" is thrown in self-reference too much. While anyone can do something clever to perform "a hack," to actually be a "hacker" takes a mind-set, not an accomplishment.
People can become hackers by taking on that mind-set, and they may very well be a tenable hacker without having been gifted the label by another.
I'll agree with many other comments though, in saying that "hacker" is a label that should only be used among folks who you are relatively certain already understand the concept. Example: Calling yourself a hacker over a business lunch with non-technical investors? Bad idea. Always. Even if you really are one.
Either way, critical thinkers should be able to condense their function to a single sentence without pulling out stigma-laden memes. They should also recognize that "What do you do?" deserves a response more four words long.