Yeah, neither company are exactly saints.
The angle I heard was that the man (whose name I unfortunately do not know) that originally designed Bratz worked at Mattel while he was creating the concept. MGA hired him away and made the final draft into the Bratz line we came to know.
Mattel later claimed that the first draft of Bratz was shot down by them, which would mean that they technically own the copyrights to the concept. This is the key thing; even if he came up with the idea for them while at Mattel, if he never pitched them, then Mattel had no right to them. It was after moving companies and then showing another draft of the dolls that MGA gave them the go. The reason why it seems so shady is that Mattel didn't make the claim until after the Bratz dolls started really dipping into their Barbie profits.
It was also about that time, which was the height of their popularity, that the Bratz dolls fell under attack for promoting a bad image to young girls for their more mature styling. I keep seeing "suggestive" getting thrown around, but, again, I don't see how they are worse than any other doll line out, even at the time when all this was going down. Bratz were just marketed exclusively as fashion dolls, which many well-meaning parents thought were terrible for small children.
Basically, the whole thing made both companies look ugly, and both companies played dirty, making the entire thing worse. As we all already know, MGA eventually won the lawsuit, banking millions and keeping and continuing Bratz, while Mattel later took a huge part of the market back with their brilliant Monster High dolls.
Speaking of...
My Skull Shores Ghoulia next to my Party Yasmin (whom is wearing a mix of the Party set and a separate clothing pack I bought with her).
I thought this was odd, but my Yasmin's hat is different than the one on all the promotional material. While hers is dark pink suede, the promos show a light pink knit.