Don't get me wrong, I think nothing bad of anybody that works in a niche. I just think of it as possible high risk for possible high reward. I might not even include COBOL because it has such a foothold in certain industries. It's just not a new, sexy language. I myself programmed in Pascal back in the day :-)

I was thinking more about some other guys I've ran into. One guy was an expert at this proprietary DB system and slowly would lose clients but somehow always found a new one - charging very high rates. I knew a guy who was quite old when I started and he was an expert with magnetic tape technology! His luck actually did run out, though, his whole department was phased out one day and he had to re-tool (and went into line printers interestingly)

It's really hard to say which of them hang on or not, I have some technologies under my own belt that I feel the same about!