Setting type in ALL CAPS isn't wrong but should be used carefully. Many fonts, especially script fonts, are harder to read in all capital letters. Script and decorative fonts can be beautiful but the extra swirls and curls often associated with these fonts make them harder to read when several capital letters appear together. Headlines set with a mix of capitals and small caps can be elegant and easier to read than other ALL CAPS.
Readability is the guiding factor when using all caps. Use all caps in moderation. Stick primarily with plain sans serif or basic serif typefaces or specially designed Small Caps and all caps Titling fonts for text in all capitals. Short headlines and other large type, such as newsletter nameplates, can take somewhat more decorative fonts in all caps.