Because the community has a bunch of redis protocol compatible choices and I don't understand why pushing redis in particular over others is the right choice.
Drew had the opportunity to make money with this fork by hosting it on SourceHut, and potentially creating subscribers out of redict contributors. Instead, he chose to host on Codeberg, a German non-profit, that is more GitHub like. I think, this alone, shows that (in this case) it’s about community and preservation over everything else.
I’d still expect the size of redict’s community to be big enough to convert some folks to paid. But maybe I am overestimating the size of that community since the Redis company took over?