I can answer your 1st question. Apple gave up on OS9. So other developers eventually, & some very reluctantly also gave up. The last version of Java for LW was quite a while ago. But LW is designed using Java & runs on Java. So with Java continuing to develop & the Gnutella network developing, the older Java used on OS9 couldn't keep up. LW was very reluctant to give up on it & only did just a couple of months ago.

As for KAzza, well my understanding is that it was originally the most popular amongst pc users & thus it was the one that got picked on.