If by ugly you mean:
1) Basic composition of the ground and decoration/details then it's not ugly, it's just bland. Not that bad if it actually serves the function it was created for (good layout for a hunting zone, quest, etc)
2) Square like rooms/passages with no detail whatsoever then yeah, it's too much.
3) The worst offender are the maps that are basically like number 2 but don't even make sense in the art style (A fire cavern with monsters that don't belong there, a city with floors/walls that don't blend together, etc - you get the point)
I prefer maps that have a good layout whether it be for hunting, questing, travelling, or shopping in a city. The amount of detail in them can vary, It doesn't bother me as long as it's not too crowded nor empty.
By good layout I don't mean for example, a thousand pathways in a cave that all lead to the main path once again, just cohesion in the place, if I can make some sort of a "lap" in different routes and that I don't stumble against rocks or too many obstacles during the hunt it's fine.
A map like Tiquanda's Jungle, while detailed and pretty, is a nightmare to walk in without map clicking for example, it serves the purpose of a jungle but it would make a terrible hunting layout.