The same kind of bonds let a compound condensate and solidify, so "only van der Waals" and similar reasons would tell why a compound both melts and evaporates easily, not why it sublimates, that is goes directly from solid to gas - why it evaporates about as easily as it melts.
My partial understanding is that in a solid, malecules attract an other through several points at once because they are properly organized, while in a liquid, only one or few points attracts them at a given instant.
In this image of liquids and solids, molecules that are unsymmetric can touch an other with an unfavourable angle, attract an other a bit, and make a liquid, but are less probable to have the favourable orientation that lets them make a solid. As well, deformable molecules can attract an other at one or few atoms, but have rarely the proper conformation to fit optimally an other and make a solid.
So stiff and symmetric molecules solidify almost as easily as they condense, have a small liquid range and can under some pressures sublimate, while deformable and unsymmetric ones condense easily but need a much colder temperature to solidify, showing a wide liquid range.
This fits observation rather well - keeping in mind that no theory up to now predicts melting points. very symmetric molecules like cubane, adamantane, benzene... have a small liquid range (or sublimate depending on the pressure, total or partial) while unsymmetric and deformable ones like phytane have a wide liquid range.