There's a long history of the likes of Redis, MongoDB, Grafana, Terraform etc first releasing their product as free and open source to get adoption, hoping to make money by some indirect means, then relicensing to closed source later on because nobody pays for something they can get for free.

And pretty much all major programming languages and libraries are given away for free too. Someone tries to introduce BitKeeper, a commercial version control system, for the Linux kernel? They won't stand for it, some's gotta clone it and give the clone away for free.

Hell, I've heard loads of people here on HN complaining when a SaaS company introduces features exclusively useful to large corporations - like single-sign-on integration - then wants to get paid for them.

There's a handful of exceptions. For example game developers will pay $$$ for "Unity" and store their assets in "Perforce" and suchlike. And I believe it's possible to pay for Visual Studio.

Every single time someone posts about some commercial tool, in a website dedicated initially to startups, there is always a set of replies with half-baked open source alternatives to use instead.

Developers regularly underestimate the work required to build something and will spend a lot of time building something themselves vs buying someone else's tool for $5 / month.

Source: Myself

It's hard because developers don't usually have spending authority or budget. Often, nor does their manager or their manager's manager. To get the company to buy something you have to escalate to an absurdly high place in the org chart and so devs will often try to cobble something together out of free stuff, even if it's far less efficient, because spending developer time doesn't require permission whereas spending credit card balance does.

Unrelatedly, there's also to some extent an expectation that everything is free, even for commercial users. The most common pricing question I get about my product is "can't you make it free for commercial projects that don't have revenue yet", i.e. effectively asking me to become investors in their own venture. Because often they want to make a product company, but not spend any money to do so.

Source: I run a small software company that sells to developers.

No, non developers are more likely to buy software for what they need for their profession (that is why tons of terrible software exists everywhere for such tasks). Ad ridden spyware is mostly for consumption things like games and random websites. On HN every now and then you will see people saying you can do anything with nano and vim/emacs and only recently some of them have started using LSP. Anything that is not totally free and open source gets 100 denials on HN.