Average "accordion patches" try to capture the look&feel of a "typical" accordion. Which lean a bit towards the awful side.
The accordion is really a portable harmonium with much more delicate pressure control (which is one reason harmoniums went out of fashion and accordions not). An "accordion patch" does not offer this minute continuous control, similar to how solo violin patches rarely crank out anything satisfactory.
Once you exit the folk music scene and take a look at jazz and tango accordionists (the original "Ole guapa!" has been composed and performed by a Dutch accordionist of great acclaim) as well as players specializing on baroque, romantic, classical music as well as a number of Latin American dance and art music, you'll find a lot of brilliant and sensual play. Nations like Finland, France, Russia have long and active accordion traditions, partly inspiring new classical compositions.
The bandonion has similarities in technique and sound and has become the Tango solo instrument of choice.
With regard to dance bands: many folk dance events make use of small diatonical accordions, and France made the chromatic button accordion large in its use for musette music. "Musette" is actually the name of a bagpipe, and for purely acoustic bands, the cutting power of an accordion rendered it a suitable replacement with nicer sound and the possibility for polyphonic play.
Accordions are still built for volume, but the use of detuned reed sets (particularly striking in "musette" tuning) with strong beating, very useful for making sound hearable above a brass band, has declined in its aggressiveness since nowadays amplification can be used for maintaining a suitable balance between instrument types.
A musette accordion without accompaniment and in original tuning is sort of an acquired taste. You really have to take it as the equivalent of bagpipes at home.