  We propose an interpretation of the gauge coupling unification scale which is
not related to any new particle threshold. We revisit Grand Unified Theories
and show that it is possible to completely eliminate the scalar as well as
vector leptoquarks from the particle physics spectrum. As a consequence, in our
approach the gauge hierarchy problem is put on different grounds, and the
proton may be absolutely stable. In order to achieve that, we employ a number
of nonlinear gauge-invariant constraints which only affect the superheavy
degrees of freedom. We illustrate our considerations in a model based on the
SU(5) group, with the generalization to other groups being straightforward. We
discuss how scale or conformal invariance may be added to our proposal.
