In the synthesis of azo compounds, given the strongly basic reaction conditions, why is the azo product favoured?

I was reading about the chemical synthesis of aromatic azo compounds, wherein, first a diazo cation is formed from an aromatic primary amine:
$$\ce{Ar–NH2 + NaNO2 + 2HCl -> Ar–N=N+Cl– + 2H2O + NaCl}$$


This cation is subsequently reacted with a phenol under strongly alkaline conditions. EAS takes place with the diazo cation as the electrophile and we get the azo compound at ortho and para positions.


What I was wondering is, since $\ce{OH-}$ is strongly nucleophilic as well (in fact, I would guess more so than ortho and para positions of the phenol anion since the electron density is being distributed via resonance), how is a favourable yield of the product we want obtained in reactions in like this? Also, why would the the ortho and para product be preferred over the cation reaction with the $\ce{O-}$ of the phenol anion?


