I believe that the explanation was (probably) appropriate. That being said, I really wish there was an ability to cut announcements while in one's room...I'm reminded of an overly-enthusiastic cafe attendant on the Starlight...and let's be frank, those can cut in on anything from a conversation with another passenger to a nap to an important phone call.
Strongly agree on this, especially announcements that are repeated after a major station stop where several new pax have come on board. Of course there is the safety element of needing to be "in range" of the 1MC, especially for those who are not train savy.
Well, the solution would be to have some sort of override built in for emergency use only. This would probably involve controls that are more complex than a physical switch (e.g. having two or more channels, one of which is an override channel that broadcasts regardless of whether your channel is on or off). This is probably my biggest gripe with the newer rebuilds: At least with the old ones, you could switch channels and nothing came through.