In general, I think I'd agree with that. I've had a couple of jobs where I've been in a position to oversee other employees - any skill can be taught, what I want to see is someone that's putting in the effort. Sure, I've seen my share of people that just aren't cut out for the job we're doing, but I'll usually try and cut them some slack if I can see they're trying. Had a little secret test I'd put to new employees when they hired in at one time. This was back in the day when I worked stock at a 24-hour grocery store. The job svcked, the company svcked (and went under a year after I left the place,) and the work was hard and fast-paced; no one liked doing it.
What I'd do was take them on a brief tour of the store, show them the back room, where everything important was, etc. I'm a fast walker at work, most of the jobs I've had are pretty fast-paced and I'd liken a lot of them to plate spinning (keeping track of multiple things at once, changing priorities on the fly as things change, etc.) So I'd go around at a fair clip while I was talking to them. The ones that kept up with me were going to stick around for a little bit. The ones that left me waiting at the end of an aisle for them to catch up (or worse, clearly couldn't be bothered to show a little hustle) would wash out pretty quick - and might not even show up for work the next day.
Any job advancement I've ever got was more through showing hustle and putting in the effort. If I was too good for the job I had, then I had to make sure I was doing good at that job - you don't get to just be a good worker at the job you want. If you can't be assed to put in some effort at a job you don't like, then you're just a bad worker and how's anyone going to assume you'll do any better at a better one? A quote I was always thought was relevant was something along the lines of "It's important to work hard. It's even more important to be seen working hard."
There's lots of different jobs out there. Of course the trouble is landing one, and that depends on the job market where you live, too. I've been desperately hunting for a new job for a little over a year now, but nothing's panned out. So I know it isn't easy.
The hours svcked, but I really did enjoy being an overnight cashier. You'd have your busy times, but most of it was downtime and if you put a little effort and initiative into finding useful things to keep you occupied it was pretty easy to impress people.
Also, in your previous post you said you were 20? I don't know of anyone that any particularly useful skills at that point in their life anyway. Skills are learned through experience, and obviously younger people don't have a lot of them. What you're looking for is someone who's going to be looking for potential, and there are employers out there who want that. It takes time and money to train good people, and most employers would rather have someone that they can train up and be a good long-term investment anyway.
9 times out of 10 I'd rather hire someone that I feel will have a good work ethic and can learn the skills needed over someone who feels they already know everything they need to know and isn't interested in showing the effort. The worst employees are those who feel they're too good for the job they have so feel they don't have to work as hard as everyone else.
And I truly believe that anyone can learn anything. It's just a matter of effort. The only thing special about a brain surgeon or a rocket scientist is the drive and ambition they had to get where they are, in my mind.
(Yeah, most of that's probably just my mid-western work ethic showing through, I suppose... I was raised that if you're in a bad situation you svck it up and make it better, because there just aren't any other options than that.)