I don't wear a maple leaf pin on me (I travel with a suitcase not backpack, beyond that being in my mid 30s with more money so I can stay at decent hotels) and haven't found people in Europe hostile.  Although I do always make an effort to speak the local language and try to adopt to local customs and manners so that is perhaps why.  In fact I got mistaken for British a few times (Yes my accent is not remotely British, but if you cannot speak English you might not know the difference just as a Canadian couldn't tell a German and Austrian apart despite accent differences) as I tried to speak the local language which Brits often do as they know not everyone speaks English, whereas Americans tend to just assume everyone speaks English.