Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

(N/A) $Benzene$ is a planar molecule having delocalized $\pi$-electrons above and below the plane of the ring.
Hence,it is electron-rich. As a result,it is highly attractive to electron-deficient species,i.e.,electrophiles $(E^+)$.
Therefore,it undergoes electrophilic substitution reactions very easily.
Nucleophiles are electron-rich species. Hence,they are repelled by the electron-rich $\pi$-cloud of benzene. Consequently,benzene undergoes nucleophilic substitutions with difficulty.