Yes its hard to be perfect and the whole 5* expectation is somewhat absurd.
The issue is about AIRBnB behaviour in not implementing there own policies which state that review must be "fair and unbiased and relate only to the stay" - nothing personal. In our case the reviewer commented they had a great time and the stay was terrific but then went on to call us out on seeking payment from them for damages. In fact what we did was trigger the AIRBnB insurance claim for the damage they did - which bye the way AIRBnB has since paid. So several issues with this.
1. Why would AIRBnB allow somebody to leverage the platform in such a personal and vindictive way
2. Why will they not back their own policies
3. Why do they refuse to answer any specific point raised - they merely hide behind generic statements of "we have reviewed this but...."
All in all it outlines alce of ethics and transparency - key issues for a platform such as this.