Players who solely suicide nade should be discouraged from doing so.
First, what is suicide nading? It describes the strategy where the player merely runs while priming a nade with the objective of killing as many enemies as possible. On the surface this seems like a harmless and legitimate strategy. However, aside from the fact that it's really annoying, there are two very good reasons why it should be discouraged.
1. Collateral Damage - Suicide naders consistently kill their own teammates and they don't really have sufficient incentive to take care to prevent that. It's not enough that they lose 1 kill for every teammate they kill because suicide naders net more kills than they lose by suicide nading. Today I asked "nobody" (the player) why he kept suicide nading when he had killed his own teammate (Swampfox) enough times to dominate him 3 times over. Nobody replied "It's war. It happens. Besides, I apologize. It's just a risk I'm willing to take." Swampfox did not seem appeased by this answer. I replied to nobody "but are your teammates willing to take that risk? After all, they are the ones being affected." Nobody responds "Who cares what they think." Zeus, the worst offender, remarked "if teammates want to avoid getting tked by us (suicide naders) then they should just stay out of the water." There has to come a point where playing recklessly constitutes intentional tking, even if followed by an apology.
2. Clears out the server - The team being subjected to the suicide nading generally gets frustrated and starts leaving the server, as I just now witnessed.
To combat this problem, you need a rule against playing recklessly. Perhaps handing out day-long bans to players who, after being warned, continue to kill teammates with their nades at an unacceptable rate.
Need more evidence this is a problem? Just take a look at the scoreboard with the two worse suicide nade offenders. They are clearly contributing nothing to their teams. Though this does tend to show that they do not net more kills than they lose from suicide nading.