To Inflate, Or Not To Inflate?

Whilst it's pretty stupid to leave a pump out that you know is knackered; I know that bikeshop don't like customers using the decent workshop pumps because someone will invariably try to inflate a tyre on the wrong valve or do something like that and wreck it.

It probably used to work until some numpty off here tried to run their fixie skidder tubs at 400psi for awesome handling and forgot to undo the presta screw.