In theory, we could set it up so that they could use either format fairly
easy....
What if we did a Java MOJO that had all the XJC configuration settings as
options -AND- had an optional <xjcTask>xjc-build.xml</xjcTask>
The only difficulty would be in ensuring that the XJCMojo adds any new
XJCTask configurations...
Offering more than one way to do the exact same thing may confuse people.
KISS principle. People may also try to combine the the two setting styles.
Its also more code to maintain.
If you consider this example...
<xjc target="src" removeOldOutput="yes" package="org.acme.foo">
<schema dir="schema" includes="*.xsd" />
<depends dir="schema" includes="*.dtd" />
<produces dir="build/generated-src/org/acme/foo" includes="**/*" />
</xjc>
This just does not seem to make sense in a Maven environment because:
1. Items like removeOldOutput and package maven users expect to set them
like so <removeOldOutput>true</removeOldOutput>
2. Many of the settings in Maven are defaulted to standards. The M2 plugin
defaults source to be "schema" and *.xsd. So for most people they never have
to configure that. With ant you are forced to define all directories and
files. It seems like a step backward by requiring all the ant settings that
are automatic in maven. Maven gets your away from that with a defaulted
directory layouts and assumptions.