Absolutely not. As a mathematician and a theoretical physicist by training I cannot see the logic in avoirdupois measures, and as a European I want to use European measures anyway. Over here, things have to be packaged in metric quantities. It's the law. Some unreconstructed reactionary so-and-so's package Imperial quantities and label them with the metric equivalents, but that's just plain silly.
Apologies to our friend Dr Zeus, but I think you'll find that the persistence of the usage of ounces in espresso measures is because of our North American friends. The fact that they don't even use "real" ounces but ones they invented themselves makes it all the sillier!
Ignore them. We're European. We can't totally ignore what the Americans do, there are too many of them. But this is one case where we don't need to care.