Why do people need a universal system of naming organisms?
Really just to keep track of everything.
The answer to this is we don't really need a universal system, but it just makes keeping track of the species we discover and study much easier.
Think of it like trying to have a conversation with four people but you're speaking english, and they're speaking french, german, italian, and swedish. Nobody could understand each other. If you all simply spoke a common language the conversation would be much easier to have.
A universal naming system for organisms just means when people from different places talk about their studies, everybody knows what species is concerned.
Source. Took AP Bio