Yeah, this issue happened a few updates ago and is back again. Nexon Security doesn't close properly and will stay open until you close it manually in Task Manager. I get the added bonus of needing to restart my computer in order to play again after closing the game once.
Look, it's like two people go to a book store; one person has a membership that gives rewards for so many purchases but only goes once a week, while the other person does not have a membership and doesn't even buy anything but goes every day and just reads the books there. The membership holder gets a free piece of cake eventually and the non-member wants a free piece of cake too, because they spend all their time there.
I mean, they're paying money to help support the game. If you're a free-to-play player, you don't really have a right to complain. Free-to-play players still get a ton of rewards for free on a daily basis.