[lotsofpulp]

> Why can't people just go negotiate directly with the sellers?

They can, unless the seller enters into an exclusive contract with a real estate agent.

https://en.wikipedia.org/wiki/For_sale_by_owner

[Jailbird]

True - I meant the unethical-but-mechanically-possible act of having someone show you the place, then being a jerk and contacting the seller directly.

edit: to be clear, I don't condone that at all, I just mean that's what I considered in thoughts about why we need laws that cover such things.