See the following section of the IBM JDK1.1 license agreement...it only permits the product to be installed on a RedHat or Caldera system. Providing an installer in Debian is simply encouraging users to break their agreement with IBM. This is unfortunate, of course, and someone ought to try to talk to IBM about it.
-- Fred Program Code Consists of the IBM Developer Kit for Linux(R), Java(TM) Technology Edition, Version 1.1.8, in Binary Code form, as modified by IBM to run on the RedHat(R) 6.0 Linux or Caldera(R) OpenLinux 2.2 Operating systems. The Program Code consists of the Java virtual machine, the Java platform core classes and supporting files (also known as the Java Runtime Environment or JRE) Java Tool Kit, Documentation and Java Samples. Program Code may include soft copy documentation, readme files, program data and such like. You may only use the Program Code if you are a current licensee of Redhat 6.0 Linux or Caldera OpenLinux 2.2 Operating systems and the Program Code may only be used in conjunction with such products. This Program Code is a "no charge" program . For each such license of RedHat or Caldera you possess, you may make a corresponding copy of the Program Code for use with that licensed copy of RedHat or Caldera.