Personally I'm a newbie and I've always gotten constructive criticism and didn't feel disrespected. I've always gotten help when I needed help. But I also try to do my own research and learn on my own before asking for help. Almost everyone here is here because they want to help. Id be annoyed if it felt like a newbie was asking a simple question easy to find on their own before they even tried and I have a feeling that's more often than we'd like to think. It doesn't pay to be given the answers and an experienced user knows this. I guess in short one I think common scenario is "if you ask a stupid question you're gonna get made fun of a little bit" - Dwight Schrute.
You made a very nice point mate. One of the most contributing factors of this being polite or not polite from the senior members is because of some questions that newbies ask at times.
You can see a newbie ask a question like "What is bitcoin", "what is the difference between bitcoin and bitcointalk" or worse scenario, you can see a newbie post that he wants to teach people how to post on bitcoin
These are the type of posts that offends the senior men in this forum and they will descend on that very newbie in different ways.
So, it is important that every newbie do some research on their own and try use the forum search button.