You constantly here this claim. It pisses me off every single time. And not just this specific claim, but what people say about polygamy in general. There was a woman on ummah forums saying she wants to marry a polygamous man, because all of the greatest Muslim men in history were polygamous (a flat out lie btw). This is how mentally unstable the woman is. And then we have the ever so famous Islam QA thinking they got polygamy down right correct, when in fact they're just bullshitting (see point number 6 and 7 here: http://mymuslimthoughts.blogspot.ca/2015/02/muhammed-al-munajjid-is-deviant-do-not.html).
Here's the ACTUAL deal on polygamy. It was revealed to do justice to the ORPHANS because many women at the time were not financially involved or educated. Many of their husbands would die because of wars, and they were the only source of protection. This isn't the case today, as Muslim women are excelling in every field out there. However, the salafi and cultural Muslims don't want to admit that, so they take incredibly screwed up views on polygamy, such as men needing to marry more than one so they don't take 4 girlfriends, or men needing to marry more than one so women can be taken care of so they don't become prostitutes (Islam QA said this).