I agree with kwun's approach.
I think it's really down to the members themselves to "behave". Once reply, just try to be informative, provide reasons, facts before either agree or disagree. If an answer of just "good" or "bad", seems really makes non sense.
As BRL stated, "I agree" surely shows some support for the previous posters, but if we can simply add a sentense or two, by say, talking about my own experience, etc, it will make the reply be more reasonable and useful.
I don't think post up examples will be good. If I ever had a post similar to that, I will surely feel hurt. To me, I think just once a while, making something off topic, or a 1 or 2 sentense joke is ok, but if this happens more often, say, half of the posts are nonsenese, that really become unacceptable.
I don't think kwun is really targetting any particular ppl here. He did not really force every post must be written in a professional way. With different background (expert, pro vs rookie, newbie, young ppl, etc), and writing skills, I think it's ok that a statement is not very well written. However, as long as the poster tries to provide some good information, it's ok. On the other hand, just one or two word of repeating the same topic without explaination is the one we are pointing at.
Also, I agree with BRL's point of "post without search". Well, that's why some members were trying to povide links (search result) for the newbies, instead of bring up the same discussion over and over again. For ppl who received this kinda reply, I think it's ok to make a mistake once a while, but if keep taking advantage due to laziness, well, don't be surprise that ppl will pick on u.
Another suggestion, some common words might not be very easy to search (say, "string" will bring up 2000 threads). However, if u can put a little bit more specific description in serach, or, just read the first 2,3 pages of threads, we can cut the "dupe threads" by huge amount.