Wow, I also had to use blueJ when I had to program in Java. It felt really weird to me as there as so many better alternatives. Any chance this was at the Erasmus University?
I always figured the tool was deliberately chosen because it gave just enough support to the learner (syntax highlighting and class diagrams) but didn't offer any other safety nets or convenience. Kind of just one step away from programming in notepad.exe :)
That's correct! Michael Kölling, one of the original authors, was a lecturer who wrote it originally. All of OOP classes were taught with BlueJ, but we were allowed to other editors, though not many did.