Hey Marko,
In my experience, there are a few common reasons why libraries do not end up in Debian:
1. Lack of time from maintainers: Debian is largely a volunteer effort, and as a result, sometimes things don't end up in Debian simply because people lack the time to package it. You can help here by learning to create packages (the IRC channel can be helpful, OFTC #debian-java) and requesting review/sponsorship
2. Licensing problems: either a library or one of its dependencies cannot be packaged due to problems with licensing (e.g. a library depends on non-free software to build it, for example, or copyright/license statements are missing)
3. Unawareness: Nobody has asked for the package before, so we simply weren't aware that someone wanted a package. So your email helps :)
4. API stability: If upstream does not maintain API/ABI stability, then that may make it difficult for maintainers to handle the package (related to #1) causing the package to be dropped :(
5. Not required by any applications: In general, we package libraries when they are needed by an application. I think this is mostly due to #1 - if it's labor intensive to package something, then it makes more sense only to package libraries that are needed by applications, since those are more likely what users will want to download. At least this was true for the Debian Perl Group, I'm not sure if the Java group has similar constraints/thoughts.
I think all packages that people use are worth adding to Debian, regardless of whether libraries accomplishing a similar purpose have already been packaged.
Other great static code analysis tools (not just for doing call-tree analysis) include:
In general, I think for development, people take advantage of Java's mature toolchain & ecosystem (Ant+Ivy, Maven, Gradle) rather than use Debian packages, so that may explain why we don't have as many.
Jonathan