You never know, in the future there may be new crafted sets released that require 9 traits to craft. So if that happens all these people creating alts so they can churn out Nirnhoned items quickly and profit will be sorry they didn't take a month to learn the 9th trait on their mains who already know 8 traits. I guess either way you're putting in a month to wait whether you do it now or in the future (if and when a 9 trait set is released) but personally I would rather do it now and on as many items as possible so I'll be ready for that in the future.
Just something to think about before you rush off to make a Nirnhoned crafter alt.
~ Belle Folie
"I'm here to kick ass and eat sweetrolls. And I'm all out of sweetrolls."