I suspect to some degree it could be about the icon that goes along with the name[0], which might seem a bit of a caricature.
Otherwise, since the project doesn’t seem to be directly referencing a tragedy and couldn’t reasonably have been named with the knowledge of the connection, how can this naming choice strike someone as inappropriate?
Fairly certain that the name and logo are both derived from the "little Hiawatha" comics.[1] It seems they never really took off in the states, but they're fairly common in the weekly Donald Duck cartoons, at in the Netherlands when I was young.
Otherwise, since the project doesn’t seem to be directly referencing a tragedy and couldn’t reasonably have been named with the knowledge of the connection, how can this naming choice strike someone as inappropriate?
[0] https://www.hiawatha-webserver.org/images/hiawatha_logo.png