Undoubtedly, itraders was an easy way to assess the credibility of a member or thread. I don't know why was there a need to create more complexity by introducing trophies, points, likes etc. Even though itraders can still be seen on the profile info page, but its not as prevalent and visible as they were before.
Trophies, points and likes didn't replace iTrader. Instant Pay replaced iTrader back in August, 2010. iTrader was still able to be used after that point to allow an overlap time where people could build up their Instant Pay ratings at the same time.
Thats what i am saying they didnt replace itrader but why add more complexity in the form points, trophies etc...Just one measure of credibility was enough.
There is only one measure of credibility for marketplace stuff. Instant Pay transactions/ratings. Likes and trophy points don't make anyone credible.