Thank you for providing your thoughts. I really do want to learn what you know. To help you help me, please allow me to be more clear in my request.
There's a lot here, and I think you're conflating a number of things. Also, as many have mentioned, publishing conventions will vary not just by type of writing (fiction/non-fiction, long/short), but by genre. For example, in SFF, you don't have to write short fiction to be able to sell a novel. Neither do you need an MFA or six weeks at a writing retreat. You just need to write and query a good piece of work.
This thread began because I was given advice in a separate thread to avoid smaller, less established publishers/publications in favor of creating good work and submitting to my target agent or publisher.
Here's where I think you're conflating some things. Small publishers and publications are fine. Scams are not. It is sometimes hard to tease the two apart, especially if the market is not yet established. There are warning signs (like the royalty structure of the anthologies you posted) that don't necessarily mean something is a scam, but do suggest you're not likely even to get exposure out of it. Meanwhile you've given up first publication rights to the piece (a lot of places, even short story markets, won't touch reprints), and all your hard work has gained you pretty much nothing.
A History of Saleable Work – each story that is picked up by an editor or publication proves that someone thought you could write and had something to say. The bigger your catalogue, the more credit you are given when you approach someone with your work.
This assertion of yours is where things get fuzzy.
Writing isn't an internship, where if you've clerked at the right lawfirms you get hired by Big Partnership and your career takes off. At least in the genres I'm familiar with, nobody's going to scrutinize your resume and reject your novel if you haven't "paid your dues."
As for what prior publications
can do for you? As I said, some agents might be more inclined to read pages if you've got a decent resume. But a credit in (frex) an open-call anthology that maybe pays royalties if the press's original costs are ever covered isn't a whole lot more robust of a credit than whacking something up on your web site. And even a paid credit won't help you if the agent doesn't like the book.
There's also a wider implication to writing for "exposure": every time you write for free, you're contributing to the downward pressure on what all writers get paid. No, one writer is not responsible for the whole industry. But anyone who isn't compensating you properly is absolutely taking advantage of the fact that the world's full of writers who really will grab any deal they can, even if it hurts them.
It is this last point, a history of saleable work that I have been working on with my son.
Here's my opinion on this: an awful lot of young writers take bad deals because the work they're producing isn't ready yet. And that can, indeed, hurt you. I'm not talking about the sort of growth we all go through as we write through different periods in our lives. I'm talking about writing that would not be considered by a reputable publisher/anthology/short story market. I'm talking about writing that would cause someone to close the "Look Inside" on a self-published book and spend their money elsewhere.
Shoot high in your markets, and in your sales/marketing when you self-pub. If you're not getting traction, don't send the piece to a "we'll-take-anything" anthology - set it aside and write something new.
I did not become a working writer. I went into business, sales and finance of all things, and became quite good at that. My advice to my son is that he will struggle in the beginning at anything he chooses, so choose the thing he loves so that when he is my age he is quite good at that.
That's good advice, but you're conflating again.
Unless you're a staff writer, writing isn't a "regular" job. It's freelance piecework, always. You're being paid, ultimately, by readers - and it's not a reader's job to finance you through learning the business. It's your responsibility to learn what you can before you reach out to take people's money for your art.
The path that I know is:
A. Earn credit through small publications and contests
B. Work open calls for submission
C. Find an agent
D. Find a publisher
E. Demonstrate your ability to repeat
A and B are unnecessary here. You can skip straight to C. I'd even say most writers who write novel-length work
should skip to C, or to a good critique group and some folks who can help them learn how to self publish strongly. (Doing both can also be a good choice; trade and self pub don't have to be mutually exclusive, as many on AW can tell you.)