My assumption: the reason serious companies will pay is that they don't want to make silly mistakes like license infringement for which they can be sued. If they want to use your lib/tool/etc, because it will speed up their development or help they make money in any other way, they will choose to pay you these $100 per year. If you gain a few (dozens, hundreds, thousands) clients like this, you're able to build a solid source of income, and since they buy a license on a subscription basis, it's likely you will keep the clients for the next year
Then the software is not open source anymore, i.e. the claim that one sells open source software is fraudulent.
Side remark: In the past Microsoft attempted to establish the term "shared source" for software where you can see the source code, but which is not open source.
Fraud requires intent to deceive. Your conclusion seems very alarmist and unfair.
This is still wrong (and likely again fraudulent, but IANAL), since the software is not open source if there are such usage restrictions. Call it, for example, "paid sofware with source available" ("source available" is another common term for software for which one can see the source code, but which is not open source).
2) The usual way to do this is to AGPL your software (or be even stricter), and sell it by relicensing it for businesses who pay you so they can use it how they wish. You don't have to make up a new "non-commercial open source" license to do this.
edit: It feels like OSS people are haphazardly stumbling through the thought processes that lead to the GPL in the first place. Once you've made an open source license that doesn't allow people to make money using the software, does it matter whether they share their changes or not when they distribute?
What's motivating people to reserve the right not to share changes in the software they distribute for free, other than to maintain a now enforced as worthless (by this particular license and similar variants) distinction from the GPL?
There are further plans, but I'm still trying to get some funding/help to have a time to continue development
Config:
1. You set up an account on the marketplace - sign up, then connect it to Stripe through the marketplace and decide which software you want to sell (about 15 minutes in total)
2. Copy-paste a new license to your repositories - You relicense your software to use a slightly modified version of MIT license, which requires commercial entities to pay for your software (5 minutes or so)
That's all for config, now your part is done and the rest of work is on buyer's and marketplace's side.
You of course remain owner of your software, you don't move any rights to marketplace or users, except the license for usage, just like you do it now with MIT/GPL/whatever license you use right now. Marketplace is only to connect you with buyers and give you centralized place to sell with automated infrastructure, so you don't process payments, signups, etc. by yourself
Selling:
If a company wants to use your software, they need to pay a monthly/yearly fee - you choose how much you charge
License:
You can customize the license if you want - you can choose whether you allow free usage for non-commercial/scientific/charity purposes and you can also set some other feature flags, so you have a control over how your software is used
And that's basically it
There's an MVP on https://poss.market if you would like to check if that even makes sense to you. Thanks and please let me know what do you think if you made it to this point. I still figure this out and your feedback is invaluable to me!