Yep, and I am more likely to go after a particular goal in a game if there is an achievement for it. Hence why I didn't bother going after all the intel reports in Operation Anchorage though I did colect all the bobbleheads in vanilla Fallout 3. The effort does seem a little pointless if there isn't going to be any recognition for it...
As for the point regarding secret achievements, if you have watched the video from the Gears of War 2 people regarding their achievements, then you will know my thoughts on them as well. I have only ever unlocked one secret achievement, that was in N+ and I think it came from dying a lot in a single level. But seriously, how do you actually go about gaining an achievement that you know absolutely nothing about?
It would be somewhat like trying to pass your driving test, except the invigilator doesn't one tell you what to do during the test...