Hi. I understand the license pedantry, but I don't think you understand the effect this has on the artist community.
You're correct to call Wigglypaint "a gift" but these people take the gift out of artist's hands and sell it back to us worse.
These sites popped up all at once, with nearly identical llm-generated text, ads and dodgy links. They usually obfuscate the origin of the program or imply the original creator is involved.
Some outright lied about being "the developer of Wigglypaint".
Artists generally don't have a lot of spare cash but even so, we'll throw a few dollars at something useful to support the original creator when we can. And a lot of people did not realize the site asking for donations is just... some random person who clumsily generated a webpage to make some quick cash when a free program went viral.
Some of these sites have committed direct art theft, too. Taking people's wigglypaint artwork from social media and posting it unlinked and uncredited on their sites to show off the work of "Their Community".
People do make Wigglypaint modifications all the time, I've done it, my friends have done it! I've spent hours of my life teaching other artists how. But we're not trying to rip off our communities with these tiny changes. (And our tiny changes are still more than most of these sites will ever do. They just reupload an unchanged version 1.3 from when the program went viral and walk away.)
"Beware of Scams" is for us. The Artists.
A lot of people are upset when they find out that the site they use or the app they bought was being deceptive about who did the work to create it because "Well, I want to support the creator..." was a major part of their decision to spend their time and money there.
Wigglypaint is free. But a lot of people have been misled so mystery scammers could make a quick buck. (And "well, it's technically legal for people to deceive you to get your cash" doesn't make it feel any better.)