Earlier quoted context omitted.
Any skill. There are bio-hackers. Lock-hackers. Engine-hackers. Clothing-hackers. On and on and on. The skill has become irrelevant. Just any skill. Attitude and style is now what makes it "hacker".
Must be a changing thing. I've always thought "hacker" without qualifiers meant "person who can code".
I've got a copy of Levy's "Hackers" on my desk, printed in 1984. The first chapter opens in the late fifties (i.e. almost sixty years ago) in the MIT model railway club.
"Hackers" are (or at least, were) people who solved problems in a particular way. A good hack involved some clever dodge around a limitation, or some new creative technical thinking to achieve a task. In code terms, someone might find a way round a memory limitation by reusing something in a non-standard way, or perhaps someone might hide some extra calculation in the fly-back time of a CRT monitor. Hacks show a knowledge and understanding beyond the standard methods, a knowledge and understanding often gathered through exploring deeply and chasing personal itches; creativity based on a more thorough understanding than just knowing the syntax. The skill good hackers tended to have was just a base knowledge that allowed their creativity to fly; sometimes someone would churn out a creative, non-standard solution purely because they didn't have the skill needed, and didn't know the elegant standard method.
A "person who can code" is not a hacker (under the traditional definition, at least). That's simply a person who can code. Some of the finest programmers are not hackers. Some of the finest hackers are not outstanding programmers. Yes, there's a broad correlation; good hackers tend to be good programmers (although certainly not the other way around), but the two terms are by no means synonymous.
If you've not read Levy's "Hackers", it's a good read.