For one, in most cases the person doesn't seem to appreciate the complexity of the terminology used - secondly, the debate winds up in cesspit of semantic circular stupidity.
Firstly, a lot of the terminology is used as some academic circle jerk to inflate the egos of those who choose to attack people's misuse of them rather than the argument they make. Secondly, you've basically described most GD threads about any subject requiring an IQ of 30 or greater to meaningfully engage in. Slug vs. snail is about the level of enlightened discourse that prevents such circular stupidity.
