Devcoin isn't doing much to support open source development, it hasn't done anything to benefit hodlers for a quite a while, people are resistant to making any changes, so what reason is there for people to buy, or for people earning coins to do anything other than sell as soon as they get them?
Worry not, that's on the cards to change over the next few months. I'll make an announcement on that soon.
On a separate note, there's been massive support @ 10 satoshis the last week or so on vircurex, and a ton of dumping into it, and it's just been replaced with another large buy offer. Someone is investing in devcoins quite heavily, although the sell orders up to 20 have grown quite a lot, so I'm guessing they've just been put down for liquidity, which is also fine, as it's given large holders a chance to cash out if they wanted to.
Out of curiosity, what would you say devcoins have done to benefit holders in the past?