I'd much rather 5 "good" words in a post over 10 "spam" words in a post. Sometimes just posting a link is more helpful then writing up something (would be considered as one word). Or when it comes to welcoming members; 10 words to say "hello" isn't really necessary, although would be nice.
Word count has never really bothered me on forums as when it comes to question/response type discussions, I always right it out in complete sentences anyway unless it's a question that just requires a straight yes or no answer, then I'll just reply saying yes or no. So really, it's never bothered me that much.
I hate boards where you are forced to put so many words into a post, before being allowed to post it. If someone is making posts that are bellow the acceptable standard for the forum they are in, I'll generally send them a PM telling them to put more thought into them, and have a chat with them about their posting in general. If that doesn't work, I'll give them a warning and that's usually the end of it. I can understand why on large forums (5k + members, 500k + posts) you often don't have the privilege to deal interact as much with members, so the easiest solution is to block all posts with less than 50-10 words. I wouldn't use it unless I absolutely have to.