Though, I will note that a vast majority of the time, if someone SDs in a fight, I'll go for a rematch. For that matter, I tend to rematch as many times as someone wants, barring a laggy connection (the only thing one learns from that is patience...). If they're kicking my ass, it might take 20+ tries, but I'll normally revel in the chance to work it up to a 50-50 (or better, in many cases-- after destroying me the first game or two, there are times when people won't strive to improve; often they'll be switching around characters or whatnot, or sticking to the same strategy each game). If someone's strictly terrible, meanwhile, I certainly give them their fair shot-- everyone has off-games or gets caught playing an unfamiliar character, so I don't feel right killing someone who very well may just be on tilt and then leaving.
If I've been playing with someone for several games, I'll actually generally not SD, as by then I'm treating it like friendly practice. I might respawn and then taunt after I SD, or start stabbing a ledge if they do-- just silly sorts of things rather than taking it seriously enough to either SD myself or be 'smug' with taunts and whatnot... though, honestly, I spend 90% of the time after someone's died just charging an Arcthunder at least... I only tend to taunt as a reflex from melee if I hit a clean, lethal smash attack. It's completely a reflex-- my thumb just flails at the d-pad the second the smash attack ends-- it's not even a matter of reacting to their KO, just adrenaline at actually landing a KO smash (on Robin, it's almost always aerials or the like instead, or Arcthunder/Thoron).
