Men's top tanks are called wife beaters because of a TV show known as "COPS." This is because most of the time they showed a suspect being accused of wife beating they were shown wearing these sleeveless undershirts. It was stereotypical to the tendency of spousal abuse and the attire.
The term 'wife beaters' was used for such shirrs way before the COPS TV show. I think i came about because so many men in movies and TV from the 1960's on up are depicted wearing them, often criminals or abusive husbands. FROM web site: Use of the term wifebeater to describe an article of clothing (as opposed to its literal use) is relatively new, perhaps originating as early as the 1970s.