In uk.railway Mizter T twisted the electrons to say:
Which is pretty stupid usage, as my plumber is genuinely a
professional (unlike many!). It's perhaps something of a foil for
talking about class, which we're still to obsessed by.

nods Another way to look at it, which doesn't suffer from this problem
is when professional means "gets paid to to do it". Thus you can have
professional $X and amateur $X, without implying that one is of higher
quality than the other ...
--
These opinions might not even be mine ...
Let alone connected with my employer ...