The problem is if you miss and hit something else you run the risk of blowing yourself up.
40mm grenades don't explode in close enough quarters, so you really cannot do damage to yourself, it's effectively a 40mm slug instead of a 40mm shot (same goes for the smoke grenade)
I got kind of bored with the grenade, shotty is more satisfying.

There was a time when I went around just killing people with the smoke grenades. A lot of people were very confused, lol. It was sort of an asshole move as you create smoke clouds all over the place.
Nothing asshole about it unless you're helping the enemy attackers sneak into your base and not getting enough kills to justify the tactic. Sure, its definitely a humiliation kill, but there's nothing wrong with that considering it takes a lot more skill and guts to do than to score the kill with a "real" weapon. (although my favorite humiliation kill would have to be the repair tool, I'm up to 822 of those

)
I have a couple hundred smoke grenade kills from times where all I was trying to do was get smoke grenade kills if only for the lulz. It really isn't too terrible of a tactic because even if you miss the kill shot chances are you still landed it near the enemy and the burst of smoke is generally enough of a distraction for you to get away and get another shot off.
40mm Smoke grenades also restock
a lot faster than 40mm greandes from the ammo box
what's up with the arsehole move I've been seeing lately of sitting in the in the home spawn and damaging/blowing up resources like the choppers and tanks?
I've seen two different players do that last week.
Maybe they're just pissed off at all the newbs that try and bother with vehicles when they'd better off learning how to play the game first before messing with vehicles?
The grenade has to travel a certain distance before it's activated. If you shoot it at a wall right in front of you, it doesn't do anything but bounce off.
Well, it doesn't necessarily bounce, if you fire a 40mm grenade at a destructible wall a point blank range the wall will be destroyed, an invaluable tool for storming or escaping a building