When the value of your $100000, $200000, $300000, or more home can be greatly affected by a someone else's declared valuation of your home, its how you get regulations.
this should be. it's a market with few sales at high costs heavily interwinded with the mortgage market.
having a de facto monopoly on what's considered a fair value, rightly or wrongly, opens up bank people and real estate agents to all kind of manipulation.
by manipulating their equation they can help lowball the sales price of an entire area, they can both profit directly out of this, indirectly through stock manipulation and even cause trouble to the whole banking sector devaluing mortgadget properties
But how does getting an appraisal license protect bank people and real estate agents? Isn't an appraiser subject to the same moral shortcomings as any regular person?
And only allowing state licensed appraisers to give value estimates does exactly what you are trying to avoid. It creates a state owned monopoly on housing estimates.
Zillow would lose credibility and it would hurt the core of their business if it was found that they company was purposely deceiving people about the value of their homes so that they could directly profit from it. They might also open themselves up to legal repercussions in that case for just plain old fraud as well.
It's easy to defraud one of the parties in a real estate transaction (usually the bank; they have the money) if the other parties, including the appraiser, collude. The appraiser is supposed to be independent, and the license is a stamp of professional ethics.
If a licensed appraiser acts fraudulently, you have grounds to sue their hinders off.
If this is a regulated activity, it absolutely shouldn't be. This reminds me of the absurd barber regulations.