If you're not a wood-tier Samurai, you're meditating in downtime situations.

Shoha is free damage to reward you for meditating, which already was free damage you were getting.

If you're complaining it's 'boring for a level 80' just pretend the double iaijutsu is your level 80 and call it a day. Except Shoha is actually not going to be useful as a level 78 ability, because it's for the downtime that happens in trials and raids--which you only get at level 80.

It's free damage, I thought we liked free damage in the dps role.