I've been wondering that too ;)
When I was doing my degree (mid-nineties) we learnt Ada as our first and main language, as they were convinced it would be 'the next big langauge'. (We did a little C, FORTRAN and Miranda as well).. There were also a few jobs around at the time (this was in the UK, no idea about anywhere else..) As far as I remember its a spin-off of Pascal or Modula-2, and isn't that old, was invented by/supported by the MoD (or DoD?)
One doesn't see many jobs for lots of less-popular languages around, due to actually not seeing many jobs at all, probably, and most employers wanting something mainstream, which is easier to get programmers for.

Such is life.
C. (Whatever this has to do with Perl)

*confesses to having not done any Ada since Uni.. *