I don't want to get into this very far, as it's already been discussed in past threads. However, I still say that there are far too many homeowners that are claiming victim and looking for someone to blame instead of just looking in the mirror, sucking it up, and dealing with their own mistakes.
My disclaimer - I'm in no way supportive of bad / fraudulent appraisers, which should go without saying.
When they need or want to borrow money, most homeowners don't care in the least how much their home is really worth. All they want is the money. If an appraiser fails to meet the magic number needed to complete the loan, the average homeowner doesn't sit there and think "Hmmm, it's a good thing that I now know what my home is actually worth, and now I know not to try to get a loan. Thank you mister honest appraiser!" ------ No, quite the opposite, they call up the appraiser and either beg and plead for a higher value to pop out of thin air, threaten to sue or turn the appraiser in to some governing body (usually the better business bureau), or just go try to find a different appraiser that can "do the appraisal right" and magically come up with the correct number.
This same homeowner a couple of years later can't pay their bills or is in upside down on their home. They're still living in the same home that they bought for $100,000 and is worth $120,000; they owe $200,000 and don't have a clue where the money went and want to blame that same number hitting appraiser that just a couple of years ago was the guy who obviously "knew how to do the appraisal right."
Let me close by agreeing with some of the other statements expressed: If you're a homeowner and actually care to find out what your home is actually worth, order an appraisal from a licensed/certified real estate appraiser, and don't mention any suggested values.
PS - pay for your appraisal at the door, so when you find out that your house hasn't appreciated 300% in 3 years the honest appraiser doesn't have to put up with your temper tantrum!