The reason why is that nice and capable people are relentlessly demonized by our left-leaning media sources.  That could be changing though with the changes underway in the US, as Canada always follows the winds from the south on stuff like that, much as they like to pretend they are so different.  We may start seeing capable people be willing to serve as conservatives again, once the career-limiting demonization comes under control (which may take a year or so until Trump gets things really rolling in the states.)