Bitterness is appropriate in a lot of different beer styles. If your beer is too bitter for the style it is usually because too much hops were used or the improper type of hop was used for the style. Bitterness can also come from grain husks and is sometimes confused with astringency.
Use the appropriate variety and quantity of hops for the style of beer you are making. Pay close attention to the alpha acid content of your hops and adjust your recipe accordingly.