I don't think the wrong use of the word has led to it losing impact, just people are more comfortable using it. A lot of people think genocide is like, the Holocaust, but nobody actually needs to die for something to be genocide. It can refer to the destruction of culture or religion within a specific group as well. Like sending first nation children to residential schools. Even if no one died in that process it was genocide by trying to eliminate the culture.

People are just more comfortable with using the word as it is defined as, rather than just the really treacherous stuff like Nazi Germany and Rwanda.