The "employment at will" doctrine at work. Terrible.
I would attribute that to the weak US labor, and its failure to do away with this via country-wide/industry-wide labor agreements make this impossible, or appropriate legislation. Many (most?) countries don't have this doctrine.
Not true. Countries without employment-at-will don't generally have extremely slow hiring processes.
> a lot of difficulty when firing employees that do not perform well
Termination for cause - i.e. failure to perform one's duties well enough - is not difficult. The difficulty would be in firing employees without demonstrable cause.