One of those folks who wants to remain nameless — because, I always assume, they'd be ashamed to have the world know they read this blog — wrote right after I posted that episode of I've Got a Secret with Kirk Alyn, the man who played Superman in the movie serials. Here's what Jerry Walker wanted to know…
Looking at Kirk Alyn's IMDB page, I see that he worked a lot in Hollywood for a while and then he had long periods when he couldn't possibly have been supporting himself as an actor. Why do you think that was? How do you think he felt about it?
I don't think very many people who decide to become actors — and really it applies to any profession you choose to pursue — are happy not to be working in their chosen profession. How they cope with this is complex and can vary a lot from person to person. There are those who are proud they had what they had. There are those who are angry or sad that they didn't have more of it. There are those who can be both in a single sentence.
But before I get into that, I should say that an actor's IMDB page might not tell you everything about how often they worked or their financial health. First, IMDB has listings that are wrong or incomplete. Secondly, there are actors have lucrative and satisfying careers acting for the stage or in commercials or who make the slight adjustment into teaching and other acting-adjacent professions not charted by IMDB. I can't find my copy of Kirk Alyn's autobiography but I seem to recall him talking about some stage work he'd done. It may not have been as bleak as you presume.

Also, a person is allowed to have more than one chosen profession. I know people who act but also paint or write or dance or perform music or find satisfaction and grocery money doing other things. Every time I see a big musical dance number on a sixties variety show done in Los Angeles, I'm reminded of a gent I met shortly after I bought my house. He was an expert finish carpenter and he did magnificent work. It was his other profession along with dancing and he ticked off a long list of shows he'd been on, including every episode of The Red Skelton Show for two seasons.
He did not think of himself as a dancer who, at the moment he was here seamlessly patching a big crack in my front door, was outta work. As far as he was concerned, he was a dancer/finish carpenter who was happy doing either and was doing one way more often than the other just then.
It's all kinda how you look at it. I believe that one of the secrets to sanity in show business — or any field where there are short term jobs and you can go months without one — is to accept the capriciousness of the profession you've chosen. And it helps if you can learn to be amused by it…or fascinated by how on Monday, you have absolutely no prospects of work and then on Tuesday, someone calls and you're on a series. It can work that way even when that Monday and that Tuesday are years apart. I've probably said this before — and come to think of it, I have a graphic I made that I can re-use here. It's the catch phrase from the old Super Chicken cartoons…
But getting back to Jerry Walker's question: It's hard to say why Kirk Alyn didn't star in more movies after a certain time period. It may be as simple as a certain casting director or producer really liking him and casting him a number of times…and then that casting director or producer has suddenly discovered a different leading man type.
Or maybe that casting director or producer just wasn't casting anything anymore. A lot of hiring is done on whims or hunches. It's about as inexact a science as you can find. I suspect that at the time Mr. Alyn was in the most demand, there were a thousand guys in this town who could have played the same roles. And some of them were wondering why that Kirk Alyn guy got jobs that they could have done.
It's just the way the business works and always will. Maybe ten dozen times in my life — and probably more — someone who had the power to hire me for a real good job told me they were going to and it looked pretty definite. And then it went to someone else…or it went to no one else because the project was canceled. I've learned to shrug and say "That's show biz." A prominent voice actor friend once told me that every time he gets a job, he reminds himself, "It didn't have to be you!"
So I don't know why Kirk Alyn didn't act more but it's quite possible (even probable) that there was no reason just as there's no fixable reason why I didn't win the Powerball Lottery two nights ago. True, I didn't buy a ticket but I don't believe that would have made much of a difference.
By the way: The above quoted question did not come from someone named Jerry Walker. I made that name up. It was actually from someone named Enrique Gardenhose.