From you UMN link:
Generally, inoculated organisms will not last long if the environment is not suitable. If the environment is suitable, the organisms are probably there anyway.
Good organic matter content along with good moisture and aeration are all that most beneficial microbes will need.
So, your own link says that inoculation is probably not necessary, since inoculated organisms don't last long in the right enviro, and are already present if the enviro is right.
Some people will believe anything a salesman tells them. WC Fields said there is one born every minute. You certainly haven't disproven him.