I don't think Lego Freinds is as "evil" as people claim it to be.
I personally believe that if you want to do well commercially, you need to have variety. And the brand did well because it presented something different which appealed to a certain group of kids. However, my criticism would be that they should expand the marketing to also target boys.
I don't really get why people act like it is going to ruin a little girl or whatever. Usually with most parents, they only buy what a kid wants and if their child doesn't want Lego Friends, they don't buy it (plus Legos can get pricey). Plus it is possible to buy Lego Friends and other sets (like Star Wars). But in the end of the day, it's just a toy, and a successful line at that, seeing how other block building brands now are making lines just for girls.