I also find it pretty insincere to brush off economic problems with the half-sentence "but those should have been manageable". Aren't there lot of nations with economic problems that aren't managable (in the sense of averting a shrinking economy in the course of a few years), even though they have their own curreny?
Finally, on the small scale, traveling is so much easier if you don't have to worry about currrency. No need to get cash in the foreign currency in advance. No need to worry about exchange rates. No need to worry about your bank adding crazy exchange fees. You can compare price to what you're used to without having to do any mental (or awkward mobile phone) arithmetics. Border regions and travelers profit imensly from the Euro.
This is pretty obvious, but econmics pieces on the Euro routinely forget to mention it.