Well, I take it you're only talking about names in mechanics, Shilsen? When it comes to names for cities, locations, people, items or anything that's campaign specific, it's
very important for me to have names that are suitable, flavorful and evocative.
That said, when it comes to game mechanics, I don't care that the ranger isn't like Aragorn even though Lord of the Rings is what brought me into this genre so long ago. It doesn't matter because this is D&D, and there are only so many words in the english language (although as a non-native speaker, I have to say that I'm constantly confounded by the sheer volume of words in the english language...)
However, as
Starglim said, a name for a specific game term should give you a good idea of what it is. Aside from that, I don't really care if it's the best possible name or not. You can, and should, as
Tonguez said, use your own names for variety in your campaign (or not, if you absolutely don't want to!

)
I like the idea of using different names for classes, races and monsters in regions of varying culture and sophistication in a world. Speaking of which, "Blood Hawk" is not the best name, no, but it is honestly quite likely that the citizens of a small peasant village hounded by these vile birds would give it such a boring name.

On the other hand, the scholars of the large cities might give it a scientific name similar to the latin taxonomy of our own world.
But! In terms of game mechanics, there is one thing that bugs me about D&D 3E. Abi-Dalzim's Horrid Wilting was renamed to Horrid Wilting! Not only is this an infringement on the intellectual property of the late(?) Abi-Dalzim, but one always has to remember that
Abi-Dalzim does not forgive.