Some people get close in pvp because they are wanting to hit you with the butt of their rifle for a chance to expose you. While it's true that yes, you can hit these people, youre not accounting for the 4 others behind him spamming CC and expose abilities on you.
Certainly it's a situational weapon. In less than the "5 Feds concentrating on you" situation, it's nice to be able to spam constant expose attacks on your opponent. With anti-hold and expose traits it's even better.