Historical doesn't really communicate much, but the tension between neoclassicism vs. the baroque or rationalism vs. romanticism are good places to start. Early American architecture was very neoclassical (for example, most of the monuments in Washington D.C.) but you don't get much baroque architecture in the U.S., as the highpoint of baroque was in the 1600's and early 1700's.
The short version is that at certain times, ornamentation has been seen as gaudy and excessive, while at other times it was perceived as richer and less boring than more functional or minimal architecture.
Some did, historicist [0] architecture for example was controversial in its time for that reason. My former university's library building [1], opened in 1905, was then widely ridiculed for being gaudy.
Say, a cathedral or similar with a bunch of non-functional ostentation?