As much as the authors would want to honor people that were important for them. Is their privilege as discoverers to choose a name.

Carl Thunberg 1743-1828 was a Swedois called the father of the South African botanic. His work studying African and Japanese plants was huge. If his name is in 250 species is because he did a huge effort to advance zoology and botany. He did enough merits and helped enough people to deserve the honor to be remembered. Science is all about being a meritocracy for the benefit of the humanity.