Current studies show that a lack of diversity in the media that is displayed to children can severely damage the self esteem of any child who is not white and male. To take things a step further, this lack of diversity also rings true for LGBT+ youth and overweight children. Along with media being geared towards white males, there are also virtually no shows with LGBT+ or overweight characters that are not used as strictly comedic relief.
Not only is this problem linked to insecurity in non-white male children, but it also instills stereotypes which, in many cases, can be hurtful to all of the parties involved. This is why media that breaks the mold is important.
"The Legend of Korra" portrays not only a strong, take-no-shit leading female character, but one who is a woman of color.
"Steven Universe" depicts an overweight child as the main character, as well as several other characters with a diverse set of body types. If you add in the numerous (functioning) lesbian relationships, you have a show full of diversity.
The all new and all different "Avengers" lineup contains a female Thor, a Pakistani Ms. Marvel, and both a black Captain America and Spider Man.
The current state of children's media is hurtful on many levels, especially in reference to the dumbing down of children's shows. Although this is slowly getting better as the list of diverse children's media steadily grows, it is still a problem that needs facing.