It just so happens that two two conjugations appear to overlap in the infinitival forms here. It is rarely informative to ask "why?" about such things. Like "what is a cran?" I mean, I know what blue+berry, straw+berry, etc. are but what is a cran? =:^) Basically, you just have to memorize them. There aren't very many of these. The answer to "why?" is usually "History."

Now ask me about хочу хочешь хочет 1st conjugation, but хотим хотите хотят 2nd conj. No, don't!