My only real exposire to Ada was a report for a class project in college. One tidbit that stuck with me is that there were a few DOD projects using Ada after it was first created which actually got done ahead of schedule and under budget. That always impressed me given the normal DOD software track record.

Also, I believe people place way too much emphasis on "popularity" of a language. If a language has enough traction to stay alive it can be valuable unless you're doing the most generic web dev stuff around. Heck there's cases where Perl still outshines modern competitors.