Dragonport is very anti-undead if only due to the period if following the war between The Crew and Vorloi which ended pretty much in the destruction of both while providing Ra-men a fresh supply of still warm corpses turned into Ra-Minions.
Those were the times when the college of necromancy ruled openly and ghouls/ghasts of the college were turned into a sort of 'city guard'.
Bill made it very clear that after years of feeding on conjuered flesh many Dragonportians suffered from the hunger of those undead who were left to roam free.
The anti-undead stigma was present even before BM II started per se but the roots of those were mostly historical.
Black Marches were called such as during the Phylactery Wars vast armies of living dead clashed, each faction was lead by a powerful lich.
After Ra-Men's defeat an anti-undead purge took place. All undead wandering openly within Dragonport should expect there being a bounty put on their head… pretty much.
All caught smuggling or dealing openly with black onyx are either exiled and in summary-executed (in case of greater quantities being possessed).
Tl;dr Dragonport is a no-go for undead who are roaming openly.