They're a fun little gimmick for certain gamers. They're not terribly important but they're not hurting the game in any way so I don't see why one should hate them. If you don't like them just ignore them,
Also it is quite the clever way to get more game time out a game for those that achievement hunters. Since some achievements/trophies requires a bit of dedication and multiple playthroughs.
Also, everyone like to feel they achieved something, which is why games are fun to being with, because they make us feel good about ourselves and makes us feel that just achieved something by defeating a boss collected enough gold to buy the in game world three times over and still money to spend on ice-cream. Achievements/trophies are just a form of conformation that "you did good kid".