The only two blaster secondaries that I haven't played are /Elec and /Ice and I would pick those before /Nin. I enjoyed /Nin for purely thematic reasons, as my main was Fire/Nin for a couple of years. But eventually I wanted to do damage worthy of the blaster name ... so I moved on from it.
Sorry Profit, but I'm pretty sure that Archery makes Ninjutsu look better than it really is, in much the same way that /Fire carries a bunch of sub-par blaster primaries. Just about everyone here is pointing out that Ninjutsu needs buffing, and you stand to benefit from that even if you don't agree with it. It's cool to defend your honor, but that's about you as a player and not about the powerset. A good player can make a bad set look better than it is too.