People have to make a living! Zep spends a lot of time working on PICO-8, Voxatron and the BBS; we pay a license fee to use these programs.
I don’t know what unity does.
Lexaloffle is a two-person company (if I recall correctly) that makes 3 fantasy consoles and a community forum to let people make, share and play games. Pico-8 games can be exported to native programs or HTML exports to play without having to buy anything. I don’t get that people feel entitled to demand even more than that.
That's extremely difficult to enforce for such a small company, and PICO-8 Games (and fantasy console games in general) are rarely profitable, so it wouldn't be enough to make a living.
If you're looking for an open source/free tool I reccomend TIC-80 (which has a pro version for 10$, though you can go to the github repo and compile the pro version for free, and they even encourage it) or PixelVision8 (although PV8 isn't very simillar to PICO8 or TIC-80 from what i've heard.)
The Unity Business model just doesn't work for this type of tool.
Unity has 5200+ employees and a net worth of 4.8 billion USD
Lexaloffle games has 2 employees and an unknown net worth.
There's an obvious reason why one is free to use, and the other is not. Unity can afford to make their engine free to use for personal use, they have massive contracts with commercial game development studios & make all their income from them. Lexaloffle Games needs money to put food on the table while the 2 of them work on the engine.