Looking at the X-Men franchise and its published books, you understand that why Wolverine gets a solo series. In fact he gets and deserves multiple series. He is in the top 3 most popular Marvel characters. And who is the other X-Men character that gets a solo series? Cable?!?!?
Would you say that Cable the second most popular X-Men character? Or does he just fit that Wolverine mold of gritty old White male character? Then the question is why does Cable get series after series? Who would you say is the second most popular X-Men character?