The ground also deosn't really stop Fires, they have been known to jump it. Let's just say it isn't the weirdest Typing thing im Pokemon. (I mean the Dragon/Fairy thing I don't even want to bring up.)
Me neither, and i always asked why Steel Type do "not very effective" damage to electric type, when it should had no effect at all and why poison doesn´t do super effective on Water Types or vice versa. Pokemon Logic is kinda weird.