If the topics don't interest me too much, I won't have much to say about it.
Besides, my job affects my posting greatly. When I'm busy, I usually only have time to skim through the boards. I'll surface every once in a while, then go quient.
Also, my English sxcks. For a native English speaker, this post takes what? 30 seconds? For me, it takes 5 minutes. Scary, huh?

It's a great disadvantage to post longer (and more insightful) arguments. Most time I just go lazy and avoid the trouble posting.