"What is up with Mantyke's catch rate?"

After having a hard time catching one, I decided to look up how its catch rate compared to others. Here is that list:http://ift.tt/2BQA826'll find that Mantyke shares the second lowest catch rate (excluding legendaries) with only a handful of other pokemon, including it's evolution Mantine. The only non-legendary pokemon with a lower catch rate is Volcarona.My question is why? Mantyke and Mantine never struck me as super rare or powerful pokemon that deserve such a low catch rate. (Another honorable mention with this low catch rate is Basculin).Edit: The beldum line is also lower than Mantyke, having a catch rate of only 3 just like legendaries. via /r/pokemon http://ift.tt/2Bjtlgb