And as usual some people get up on their nerves and feel like answering irrelevant comments instead of moving on.

I'm not the slightest bit unnerved by your comment. But if you feel like answering the original question I posed then I'm all ears.

Even if I indulge your fantasy for a moment - Linux (amongst other systems) has provided myself and many others with a solid career for the better part of the last 25 years, daily security patches from vendors and all, and I don't see any solid evidence of that changing before I retire.

Further I suggest most Linux people would be able to adapt if the world were to move on to an improved competitor with enough momentum to be adopted en masse - which hasn't happened.

That has nothing to do with its technical capabilities, rather a free beer UNIX clone, that is all.