It might not be the best idea all the time, but I understand the drive to 'catch 'em all' a little better now.
I will admit that the last time I spoke about achievements they were not painted in a flattering light. I'm not going to stand here today and say that I was wrong or misguided: I still think that some achievements are deeply flawed and that achievement systems overall could stand some more work. I do however have what I'd like to think is a better understanding of some of the reasoning behind such things from playing The Binding of Isaac.
To elaborate, I've actually played BoI so much that I have all but one of the achievements for it -- the final achievement that I have to unlock requires simply dying 100 times -- and assuming that I do get that achievement before the expansion comes out and adds more then BoI will be the first game to my knowledge that I've ever gotten 100% of the achievements for. I'd honestly be lying if I said I didn't feel a little pride in my accomplishments (although it's hardly the kind of thing I'm going to put on my resume under most circumstances) but I think that in unlocking a majority of the achievements for the game that I've come to see some of the point in doing so; even if I'm never actually compelled to do so again.
It goes back a long way, to the moments when you and your friends would sit around trying to beat each others scores or best times or best runs for levels. In those days you either had to convince someone that you had an incredible run -- not an easy thing to do in and of itself -- or have witnesses that were willing to back you up. Achievements these days do some of that for you; for example BoI has four achievements based around going through a section of your playthrough without taking any damage; some of those achievements are rather difficult, especially the ones that are for the later levels. Once you have that perfect run though, there's no longer any reason for anyone to doubt you: simply point them towards your unlocked achievements and let them do the talking for you.
I know that as before nothing you can say or do can force anyone to actually care, but if people are interested then it's something that is far easier and more reliable of a source of information than a gaggle of your friends saying "Yeah, he totally did that that one time, we saw him." It can give you a certain legitimacy, in that if you have advice to give on the topic it's likely to be sound, even if that advice is in some cases nothing more than "be really lucky".
I wouldn't say that the achievements in BoI drove me forward, since a lot of them are unlocked by meeting the circumstances to get new items. The drive to see what these items do is the main motivating factor, but in this case I believe that the achievements are being used correctly: to add some incentive to do things like no damage runs if you want to, without being overly intrusive. If I hadn't enjoyed the game then unlocking all the achievements in the world wouldn't have made a lick of difference, but since I did it served as a nice little bonus, something that said "hey, he's not half bad at this thing if anyone cares."
Like I said, it's not going to change my perspective that achievements overall need a lot of work, but it has made me understand them a little better, which never hurts.