Humm. You shouldn't have a blower failure like that unless the humidity is massively high... I am a HVAC manager at a good sized 20 year company, and we service units in high humidity environments fairly regularly. Restaurant kitchens, gyms with indoor pools, and where I live, high humidity is a fact of life anyway.
We do see "some" additional corrosion on "some" components, but never a premature failure.
The only way elevated humidity could have an impact is if condensate was collecting on electronic components in large enough volume to create a short...
That typically only happens with incorrect blower speeds (too slow), improper duct sizing, (again, too small) or some other air restriction - like dirty filters or too many registers closed.
You may ask your HVAC guy to verify the correct fan speed, and duct size to be sure.