It's a double-edged sword. A year ago I saw Sho Nuff's card had 40K, and I thought "That man plays way too many games," but here I am closing in on 40K now. 
When I see someone with substantially more Gamerscore than I have, especially if they've been on XBL less time than I have, it makes me worry that they're a weirdo. That they're MORE of an obsessive freak than I am.
If you want to wean yourself of Achievements, start buying games for the PS3. Trophies are truly meaningless when you start getting them. The trouble is you've "invested" yourself in Gamescore and it's preventing you from not only playing your Wii games, but from even really enjoying the 360 games you're playing. Someday soon you'll hit bottom, you'll have a realization that it's a waste, and you'll fire up the Wii or PS3, of nail some chick, or go for a swim in the ocean, and you'll reset your perspective. That's what happened with me during Assassin's Creed 1, and while I still like 'cheevs, I'm not so hung up on them anymore.
überLOL at myself and "being over" Achievements.
My last night in California, after finishing
Castle Crashers for the first time ever, I fired up
Dishwasher again just to get an 11-point Achievement which had eluded me for the entire two-weeks of my vacation. I'd only fired up that game again because I'd previously only had a total of 10 GS in it, and thought I'd just easily get some more while I could. Having that damned game fire off OCD-triggering numbers in my GamerScore, and I was suddenly obsessed with not letting it win. Instead of playing a number of other things, I kept hammering on
The Black Book Achievement.
When it looked like I
finally was going to clear the Achievement, I was experiencing some of the most intense adrenalin nausea in 20 years. I was so worried that I'd blow it and have to try again, after having tried it maybe 60 times. But it unlocked, and I was relieved... and realized that I was actually angry that my own brain couldn't be leashed enough to not care about this stupid, non-divisible-by-five GamerScore problem.
None of this even begins to deal with the hoops I'd been jumping through for
Doritos Crash Course, and the bug which kills the two hardest 'cheevs for gamers who have purchased their DLC.

edit: teh grammerz