Yeah, that's definately a spam bot.
The Gamerscore isn't really important to me, but it does spur you on and makes you feel like you are playing for a reason. It's just a fun addition to games. There is only one game I have maxed out the gamer score for, Oblivion, and that's just cos by the time you complete it you will have all the achievements anyway. The only game I have actually tried to get 1000 on is Bully, because I knew I could and love the game so much. I got to about 750 before giving up on the horrible bugs and glitches and going back to the PS2 version.