The insurance adjuster goes for damage payout claims for an individual homeowner and their insurance policy.
The appraiser goes out to see if the collateral (house or condo) is still standing or what extent of damage it has for the lender's investment portfolio purposes.
Just like you said,
"why people want to take on the role of expert about piers and foundation issues." I have the same opinion and natural disasters and property damage, to me, I am NOT an expert as to what extent of damage a property I appraised 2-3 months ago may have, as I appraised the property as of the effective date of the appraisal report and NOT what may happen 2-3 months after the appraisal report was completed, if the lender is worried about what extent of damage for investment portfolio purposes, then they should send a casualty expert out to the property and not an appraiser, in my opinion, that's not my expertise and out of my scope of work.
To many on the lending side think that appraisers are one stop shopping, they want estimates for damage, cost to cure, explain if something is dangerous or can have a negative effect, explain the dangers of drywall from China, I actually had a client want me to state in an appraisal report that an inground pool with no fence around it is completely safe and that nothing bad could possibly happen. Again, this is just my opinion, as a wise appraiser told me years ago,
it's an appraiser's job to REPORT, it's the lender/clients job to make a lending decision based on what we report to them, if I go back out to a property after a disaster and there IS damage, then what? What can I do? Give them an estimate for everything I see, roof, HVAC, broken windows, busted pipes, I would just be throwing darts at a dart board, as I'm an appraiser.