No one is flamed on FR because of a recent signup date. I've been a newbie twice, and neither time did I encounter any rudeness solely on account of being a "newbie".
Most noobs who receive the treatment, do so because they are liberal trolls, or mistakenly think (although I don't know how they can remain ignorant of FR policies if they've lurked more than once) that FR is interested in liberal/leftist viewpoints.
I have NEVER in my admitted many hours and thousands of comments made on FR seen people hassled, harrassed or otherwise nitpicked or assaulted solely for being noobs.
http://www.freerepublic.com/focus/f-chat/1234374/posts
this was the thread I took offense to.
I am happy that you have not seen or been party to any of this, it's good to know it doesn't happen to everyone.