Perhaps another analogy or two. If paint contractor only paints front and side, his fear may be that others seeing the job will figure he either was too lazy to do the whole job or was run off for doing a shabby job. Many contractors would eschew doing anything that might be visible and suggest to the general public that the quality of their work (which relates directly to the amount they can charge) is substandard. Likewise, a mechanic might refuse to guarentee his work with parts you bring him. Same reason. He is not going to vouch for the quality or condition of parts you bring. He is going to use quality parts because he does not want you coming back 3 days later saying it does not work and him having to stand behind his work for free over a defective part.
Surveyors are expected to perform to one standard AND BE RIGHT. Title Insurance and opinions are expected to be to one standard. Anyone hear of lenders cutting corners on surveys. "gee, mr. surveyor can't you just run a quick wheel over the boundary lines with your hand compass and call that a survey? and charge only $200??" Or, "Standard Title, please write a legal for the property. Don't worry about checking records, we're pretty sure there are no liens, so just certify it.....and if you find a lien, CALL BEFORE YOU PROCEED. We will not PAY IF YOU GO FORWARD."
In my opinion, the 2055 is a substandard product, approved by fannie mae or not. Further, if you certify that you did an exterior inspection, but only as a drive by, the question is did you really do an exterior inspection. No, you inspected the front and possibly that part that is visible from the road. Few subdivisions in my region have alleys. Many have wood fencing. Can you tell what is even there? Pool? Covered patio? whole back of house without siding?
In court when the lawyer questions you about the Exterior inspection that you CERTIFIED THAT YOU DID, and asks what was in the back yard and what was the condition of the [roof, septic, pool, etc.] whatcha gonna say? "Well, your honor, when I say I did an exterior inspection, I really meant was an inspection of 65% of the exterior and I have not a clue about anything else."
It is what you did not see that magnifies your liability, not what you do see. Any appraiser who even does 2055s, in my book, is capable of doing el cheapo work [and that includes me]. It is like comparing a $69.99 Macco paint job to real craftsmanship from a reputable paint shop. We are undercutting ourselves without any reason to do so. If appraisers refused to do 2055s, then let the brokers do BPOs for $50. When the default rate points its finger at brokers then the clients will want real appraisals.