I'm not the AC, but I have some commentary on the issue.
My position is that the GPL is inherently toxic to the economy, specifically to the portion of the economy that consists of opportunity to earn from creating software. That very economy is important to those of us who can program at a level where we can create commercial products. My tiny sector of said economy shall not be poisoned thus.
And before someone says "yes, but you can charge for support", the way I see it, the optimum path is to write software that doesn't need support. Why?
First, because that's best for the consumer: good docs, good performance, high reliability, minimum bugs, secure. I prefer to charge for the product, fix it for free if it breaks (after all, I sold it with the idea that it did X under conditions Y...Z; I maintain that's an obligation I must address if I possibly can), and charge for actual new features V...W. Likewise, if I write proper documentation (which I also maintain is my obligation), I don't need to be telling people how to do X, because I already told them how to do X. Not that I don't end up pointing people to the docs on how to do X, but that's not a failing of mine I have to be concerned about having foisted off on the consumer.
Second, because it's very good for me. If my users come to think of my products as reliable, well documented, fixed for free quickly if broken, and overall functional as advertised, they're a lot more likely to come back to me than if I continually charge them for doing the above things poorly. I'm not guessing here: This has worked extremely well for me.
What isn't good for the consumer is when Joe(anne) programmer looks at an idea, runs into the GPL, and goes, "no, not going to give my ideas to my competition" and wanders off elsewhere.
Licensing code under a non-copyleft free license means you are fine with someone taking your code and building a commercial product with it, and never giving it back in any way or form.
You contradict yourself. The opportunity to get a return is absolutely there. If Joe(anne) builds a commercial product, I have the opportunity to purchase that result; to encourage and benefit the programmer(s) who built the product in direct return for the benefit they provide me, and perhaps to benefit yet again further down the road as they consider the opportunity to earn more. Likewise, if it's me doing the programming, I'm one heck of a lot more likely to consider it if it means my family and I get to eat because I created something useful to someone than I am if my earnings are now compromised by having handed my work to the competition.
If you're okay with that, how come you're not okay with someone who does give it back, except in a way you can't use?
Because it represents an opportunity to earn; because it represents an incentive for the earner to make something for me, right along with a reason for them to do it. And I can use their work. Commercial products are usable. Writing code isn't the only use of code. Using the programs the code is incorporated in is a significant benefit. I can't be writing every program I use. Commercial products have been a huge boon to my career and my family.
Now, none of this means that I object to someone else's decision to license their stuff under the GPL; that's their code and they are absolutely free to license it any way they see fit. What it does mean, though, is that spotting a GPL license means I'm going to walk away from whatever it is. It won't benefit me in my commercial applications unless I give away my own inventions, and it has the potential to harm me by giving my work to my competition, so: not having any.
Personally, when I make code public (which I've done a bit of), I make it public, as in, you want to use it, copy it, learn from it, incorporate it in your commercial product, you just go right ahead, and I am happy for you. Because it pleases me that someone would benefit from code I publish. Financially, learning (and so hopefully financially in the long run), whatever path they want to take.
Rewards "as fame": You can't eat fame. 15 minutes or otherwise. I would encourage programmers everywhere to think through the financial implications of giving away their inventions. Implications that land on others as well as you. If you want to do the most good, as I see it, the most likely way is to open that door as wide as possible, so as to not hamstring the recipient(s) of your gift(s).
TL;DR: I won't use GPL source code. You can use GPL source code, and I don't care. The reason I won't use GPL is because it poisons commercial code with a toxic requirement to publish your own inventions.