Another alternative is to have crafting specialization follow a "branching model". Posted idea here.

Basically after 50 split each craft into a multiple subcrafts, each of which has to be ranked up separately.

Crafting jobs x 8 just means eight times as long to rank up EVERYTHING as to rank up a single one. Branching means exponential time to rank it all up, but still allows a player with more limited to time to specialize and reach high rank in a single craft.

For those that want the arithmetic...
Suppose each craft branches into 3 specialties at rank 51, and each of those branches again into 3 more at 71, and again into 3 more at rank 91. Each original craft ends up with 27 specialty branches at rank 99. Since the majority of the SP required is at the far end, this means to get all 27 specialties maxed out is 27 times as long as that required to max out just 1.

For eight current crafts, 8 x 27 = 208 times the time. So, if it takes 2 months to one specialty branch maxed, now it takes 34 years to max them all out.

And it's not hard to tweak the numbers more. Add 2 more crafts. Make the branching factor 4 instead of 3. Now its 10 x 64 = 540 times the time. Reduce the time (for some insane powerleveler) to max a single branch to 1 month. Going to take 45 years to max out all 540 craft specialties.

Thoughts?