Let us look at what was missing (basically what has been added since) excluding missing stuff from the libraries such as collections etc. (what I mean is stuff that a 3rd party can provide like a collections library or things like that) Note: this list is off the top of my head by no means complete, and in no specific order.
1. A completely brain dead event mechanism for the AWT which had to be completely redone in 1.1
2. No support for printing (not very useful to have an application that can't print anything), clipboard (copy/paste), etc.
3. No support for reflection which made it very hard to do any kind of generic or meta programming
4. No JAR file format, you had to ship the whole directory structure
5. No RMI
6. No object serialization
7. No JDBC (not much use as a business language if you can't access a database)
8. No internationalization support
9. No I/O character streams
10. No reference Objects
11. No fine grained security (either sandbox or not)
12. No JNI (which made it very hard to write native code)
13. No inner classes
14. A brain dead Date class which case all kinds of problems if you worked in more then 1 time zone
Based on this (and I know from experience in trying to write apps in 1.02) it was almost impossible to write any kind of serious application 1.02, eve Sun admitted that. On top of all this, it was incredibly buggy.