There is Samurai players evolving in the top ranks so it does perform. I think everybody agrees that it's a little underwhelming on some points (especially the LB), but shredded by every class? If I play ranged and I have a samurai harassing me I take it very seriously. If they know what they're doing they'll shred you, because by essence of being a melee dps, they soft counter you, and SAM has a lot of tools to chase (3 dashes + a bind + stun, which is more than what almost everybody else can claim to have).

But it is indeed the least survivable melee DPS which tends to make it be a lot less durable on the frontlines, and the cast times require surgical planning.