...i can only answer for myself (obviously...),and even such,the "answer" might not really cover much.
Regarding history...when MDL started back in late July 2007,there simply was almost no public place at that time,
where people could submit direct links to malware,and discuss about them...
doing so was a prohibited action in most security-related forums (mainly in order to protect inexperienced end-users).
Thereby,since advanced users/researchers didn't had the ability to do so...MDL came in to fill this "gap":
a site where advanced/technically-aware people can freely submit direct links and discuss malware,without censorship...
So,at least for that part of the story,this goal has been achieved...
As to the current goals,well,up to a certain degree,it's a community effort that is based on spare time...
so my guess is that most of us around are open to new ideas/suggestions etc.
Eg.for myself,the main goal is to keep alive the community spirit to say so...
by helping newer reversers/researchers to get involved in malware hunting/fighting etc.
To put it in the most simple terms - i prefer a community where people learn to hunt,analyze and blacklist malware,
thereby making eventually the net a safer place,instead of wasting their time and resources,
say in order to crack the billions of useless 30$ shareware apps out there...

Not all info should be public obviously - but no sharing of info at all,eventually means no knowledge at all...