Mostly people want it to join the signature and bounty campaign. One part wants it to create trust for others in currency exchanges(In this case I think feedback is of more importance.)
Indeed most newcomers that come to this forum want to rank up for that purpose although there's no much campaign which accepts jr members. In regards to currency exchange with the others I think having jr member or higher rank doesn't immediately increase the people trust on you and as you said before feedback is the most important in this case, it's worthless if you have lots of negative feedback even though you are in a high rank.
However begging for merits is the wrong way to rank up no matter whats the reason behind it.