All right, I'll pop in here I guess. This has obviously veered incredibly off-topic and I can absolutely forgive Armstrong for using that language so many years ago.
Now, that being said language is powerful and inclusive language is important. I wouldn't dismiss this as a problem so candidly. Just registering my support for Tieno's issues so you don't dismiss them as a lone super-PC-police-person.
Also, "that's just the way (the word is used)/(it is)" has never been a great defense of using non-inclusive language. Or anything, really.
At that time, it was commonly understood that "men" in such a context included "women". This was before womens' lib, etc. English is an evolving language; basically, 43 years ago, "men" in this use meant something different than it does today.
A few questions though. Would you be displeased at someone saying "Hey guys!" or "Hi fellas!" or "What's up, dudes?" to a group of mixed gender?
Do you feel that these greetings play a part in entrenching patriarchy in a real way?
Do you feel that a protest against such greetings would play a part in overcoming patriarchy in a real way?
Do you think it matters if the greeter knows the group they are greeting? If so, does it matter because of actual familiarity or just formality?