  There has been an attempt to revive the visible QCD axion at the 10 MeV scale
assuming that it exclusively couples to the first-generation quarks and the
electron. This variant of the QCD axion is claimed to remain phenomenologically
viable, partly due to a clever model construction that induces tree-level
pion-phobia and exploits uncertainties inherent in the chiral perturbation
theory. We confront this model with the cosmological domain wall problem, the
quality issue and constraints arising from the electron electric dipole moment.
It is also pointed out that the gluon loop-generated axion-top coupling can
provide a very large contribution to rare $B$-meson decays, such that the
present LHCb data for $B^0 \to K^{*0} e^+ e^-$ rule out the model for the axion
mass larger than 30 MeV. There is a strong motivation for pushing the
experimental analysis of $B \to K^{(*)} e^+ e^-$ to a lower $e^+ e^-$ invariant
mass window, which will conclusively determine the fate of the model, as its
contribution to this branching ratio significantly exceeds the Standard Model
prediction.
