You've got to take account for the fact that not everyone realises you can search on forums, espescially if they don't use them often. Younger kids don't have experience on the internet, and so don't understand how forums work.
It could also be laziness to I guess, but I think it's more of the former.
I can't really answer the first one, but it's possible that the posts are being mis-interpreted. It's hard to convey emotion within text, and so they may just be simply debating their choices and it come across in an entirely different way.
For the second part, it's all voluntary and it's what makes a good community. Helping you fellow airsofter is not necessarily mandatory, but doing so improves the airsoft community alot. Of course, no one expects help, but it's nice to have it every once in a while. Isn't that why we're all here? For our passion of airsofting and sharing that with others?
I don't think that's got anything to do with the current times, there'll always be naive / rude people, regardless of age.