Maybe there are some reasons for losing jobbing:
1. Gold is under inflation atm, trader makes a trade with less profit than before.
2. Silk is over double than before (buy silk pet), then trader makes a trade with less profit than before.
3. I am not pretty sure because I'm full thief from beginning but heard that Hunter get less HD than thief.
4. There are many ways to obtain gold => Trade with small profit is not attracted ppl, because they can go with Dungeons, FGW,... and get fixed good item for sell, it is better than trade.
=> Solution: Increase award for Trader and Hunter by double gold and HD (if any).
I know with that way gold will be inflation more but at least it keeps JOB up. We know inflation will be increase time by time, we cannot avoid it but we can make it as less as possible.
And the key thing of Sro is JOB!!! So, we should focus on that firstly.