Are PS3 Trophies Necessary

When the PS3 trophy system was released some games had to be patched to be included in with a user's trophies. The downside was the user had to play the game completely over in order to display any achievement from those patched games. I'm not sure about other gamers but I wouldn't go through a game again just to display the trophy on my user profile. Yet if the game is something simple like a Tom Clancy game then I guess it wouldn't take you long to earn a trophy; even though is shouldn't mean that much to you if the trophy is really that simple to attain. My point is that PS3 trophies are only for bragging rights amongst friends. So the majority of PS3 owners will only show those trophies to a few people within their network of friends; to me it seems like the value of those trophies is not great enough to work hard for. If they had a higher value or reason for attaining then more users would care.