Diversity on prime-time TV is increasing. In the recent years, you can tell a difference with even everyday television. As more and more things in society become open and understood then even more TV programs will air it. Look at all the reality television shows that are on now. They are helping to create more diversity.
I think that we still have a long way to go until everyone is equally or proportionately portrayed on television, but things are getting much better. There are more gays and lesbians on television and more people of color. Roles for women are also getting a bit better. They aren't always playing the same stupid stereotypes that they often had in the past.
Yes, diversity on prime-time TV is increasing, because people want to watch diversity. On American Idol, the winners have often been African American or some other minority. There are many shows, both on network and on smaller channels, that feature minorities on that are targeted for minorities. Prime time TV is not lacking for diversity.
There is no question that televison is increasing in diversity. Look at shows like Modern Family where you have basically all diversities covered from gay, Spanish, Asian, and old fashion. There are more and more shows incorporating diversity in prime time because it is becoming more accepted in the world.
I believe that diversity on prime-time TV is increasing. There have been times in our history where only white people were on TV, then there were white TV shows and black TV shows. Since then we've moved to show heterosexual relationships in more natural and common matters. Now, I think you see a more common mainstream theme, which is far more in tune with reality.
TV is more diverse racially and sexually (someone gay in tons of shows) but that is the extent of diversity. There is very little diversity when it comes to the characters themselves. Religion, conservatism, controversies, debatable topics...None of this type of diversity really exists.
There is diversity based on what people look like but not based on ideas and concepts.