vulgar taste; lowbrow taste
Refers to a preference for things considered crude, unsophisticated, or lacking refinement. Often used critically.
I think the decorations in his room are in poor taste.
That flashy tie is a perfect example of vulgar taste.
低俗 is a na-adjective meaning 'vulgar' or 'lowbrow', often used for content or behavior, whereas 俗趣味 is a noun describing a person's taste.
Compound of 俗 (ぞく, 'vulgar, common') and 趣味 (しゅみ, 'taste, hobby'). The combination straightforwardly yields 'vulgar taste'.