It's because 90% of what is written is utter rubbish. Most will have a casual glance and see if there is anything useful and after finding that there isn't they get on with other, more productive things.
Other post well and are pulled apart by the regular 'trolls' for daring to have an opinion that differs to there own.
In the 10 years I've been using this forum, on and off, it has gone to the dogs somewhat.
I think forums are like pubs, they become what the regulars make it.