@Ruel K. "trust but verify"
It's not like that with all brokers. I assume you're looking at bottom of the barrel listings that have been listed for a while and aren't selling. Those listings just stick out because they're priced terribly and are hoping to trick someone into buying. There are a lot more properties that don't last forever because they a fairly priced and realistically represented.
I always try to represent my offerings in the most honest and accurate way possible. Misleading numbers are a waste of time for everyone involved. Buyers can see through it, brokers have more trouble selling because of lost credibility, and sellers have to wait longer to sell because the property is marketed improperly.
I'll come at it from another perspective and say some buyers are too conservative to the point where it isn't realistic and they'll never acquire anything. Being conservative isn't bad thing (especially you're newer), but you want to be conservative and accurate at the same time. I've seen fancy excel analysis spreadsheets/models that churn out pure crap and make a legitimate, cashflowing investment look like a money pit that would push an owner into bankruptcy after a few months. I'm all for being conservative and feeling comfortable with making an investment, but there's got to be a balance.