What is a "professional" camera?

I hear this all the time. I have a "pro" camera, she has an "amatuer" camera, he has a better camera ....etc etc.

This is all a bit irritating, really. I shoot with Canon equipment, and most of the time any Canon DSLR will do. The question in my mind is this; Will it do it tomorrow?
Ok, "pro" cameras have advantages, sometimes. Consider though, the "pro" camera bought by a working photographer 5 years ago. It has 8 or 10 megapixels, it lacks anything like 8 frames per second, 60 point autofocus, articulating screen, hi-res rear panel, video, etc. Does this mean it was, and no longer is, a "pro" camera? Seems to me we can get higher resolutions and video for very little outlay today. Clearly a 5 year old camera can't be a "pro" camera anymore!
Then, we have the Canon v Nikon issue, the crop v full sensor issue, the "mirrorless compact" issue, and 100 other stupid arguments.
As I said in paragraph 1, some "pro" cameras have advantages. Often these are:

1/ Connectivity and accessories

2/ Body strength
and,
3/ Reliability in rough use.

If I take my cameras out and they get bumped around, heavily used and handled, I expect them to continue to work. That, to me, is a "professional" camera.

Picture taking ability? Rarely more than a 5% difference.
To quote an old cliche, it's the photographer who makes the picture, not the camera.

Would Shakespeare have been even more famous with a better writing implement?
Ansel Adams with a Nikon?
Would Susan Boyle have been better off with different microphone?
It's all nonsense really, most of the time, don't you think?
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