All forums are filled with these types because it is the internet and women are men and children are adults and despite what you are told not everything you read is true. This forum is pretty tame compared to some of the others out there. New guys are not shunned unless they deserve it, and no one is called nube for failing to search.
And yes your point is correct to an extent we are all somewhat righteous being owners and whatnot. Are you saying that you've never bid a job and after not getting it drove by and thought how you would have done it better? I get your point of proper delivery, but we've all been around here for a while and this is no secret that forums are a mix of all types.
I do not really think anyone was intentionally being rude with any of the posts. There were many compliments, myself included complimenting the water feature. Some, mine included might have been cold and to the point, but it is an issue of the reader being closed to comments as you pointed out. That is an issue with the reader themselves not being able to pick through the comments to make something constructive out of it. Now if the poster puts something up expecting all "good jobs" and "well done sir" than they will often be disappointed cause well this is the internet and even the old lady next door is going to have an opinion and you will never make everyone happy.
I do ask you this though. Will you ever construct another patio without addressing how the stairs will be part of it, or build a raised patio without thinking about your liability in a fall scenario. I certainly would hope not. If so than your own cockyness is getting in the way of making you a better operator.