In all fairness to Spark Health, they’re not demanding to use it for free (so far), but they are demanding Thomas license them to use it. The problem isn’t with compensation; it’s with the artists’ self-determination of his work. The problem with compensation models that take away that self-determination is that it treats the artist’s work as not really his own based purely on its popularity.
I do sympathize with the arguments based on the wider cultural significance of a symbol, though I’m skeptical of the notion that flags are fundamentally unique. Lots of humans love us some flags which when done well yield simple easy to recognize designs fluttering in the wind. But placing them in a different category from other symbols, and therefore other works of design, seems arbitrary and backed up by little more than that lots of groups from nations to summer camps like to fly them for identification and signalling.
The cunning use of flags (to quote Eddie Izzard) isn’t intrinsic to them. Some cultures have not used flags that way, and many that do once used something else (like banners). I find the argument that because you put it on a piece of cloth and raise it up on a poll or drape it over something that it then becomes communal property uncompelling.
