Than where is M$ getting the ones they use for the Zunes? I have several Zunes including one of the originals (that I got the first week they were out) and have had ZERO issues with any of them and several of them have been abused (the original one severely). The original has also always doubted as my care media device so it has a ton of hours and thousands of connect/disconnects. They are out there, Moto just refuses to put one in the phone. Also I've read from others (that have looked in the phone) it's not as much about the adapter as it's flimsy connection to the board (just a few small solder joints, no real solid connection or mount).
So I was looking at teardown images and it LOOKS to me like the droid headphone jack isn't even attached to the board at all!! It kind of looks like its only attached to the back end of the phone and it just 'rests' on the board connection areas. They probably do this so it has a little more give but those pins must be lifting off the board as they get older/less flexible/bent whatever.
Take a look at
http://www.phonewreck.com/wp-content/uploads/2009/11/Droid46.jpg
The ZUNE has a ribbon. Take a look at this ZUNE hd teardown pick
http://s1.guide-images.ifixit.com/igi/NmCoGApC4PNsLqrZ.large
and here is the ipod touch
http://s1.guide-images.ifixit.com/igi/XqLrUHgSEYERiT4u.large
For the apple and m$soft products the headphone jack is physically connected, not just resting on the board.
So I take it back, the issue isn't the jack, or the quality of the jack, its the way that the jack is meant to stay in contact with the board.