Hi John
As you probably know I am not a newbie. I am a scientific researcher. Programmer. Genealogy experience - intermediate I would say - since 2002. I do it in my spare time. I had 2-3 years pauses.

But you are right, there should be a more evident disclaimer about quality of data available on this site (for Newbies - but not just for them).

"This trap"
The trap is more complex and interesting to investigate and to discuss from an ethical and practical point of view.
Everywhere in this website (and in others website), we rely on available informations and sometimes the same information (true or false) is always presented over and over.
Without contradictory facts - So they becomes accepted fact.

Who build trees and make them available to others and to newbies?
People who think they are experienced enough.
A lot of us - even if parts in our trees are very uncertain - and this is normal and humane.

So as you say all: verification of sources is important. Multiple verifications etc...
In French we say "Faites vos devoirs" (Do your homeworks).

But, in reality, who can reasonably verify (up to the origin) his identity to Louis XVI or to Richard the Lionheart. Do oldbies on this site have suggestions to do it ?