I used to get steamed that magazines like 'People' would always point out when children of celebrities were adopted. As in, 'the adopted children of Tom Cruise and Nicole Kidman'. I don't know if you noticed this, but that has largely stopped (at least in People). The adoption community spoke up and the magazine listened. Adoption is still mentioned but usually only when it is relevant to the story. That is a change for the better.
Back to Modern Family. Recently there was an episode, where part of the story line, was one sibling exacting revenge on another sibling by convincing him that he was adopted. Now, I know this is a sitcom and I will admit that the way that that story line was carried out was funny. I also will admit that if I were not an adopted person and an adoptive mother, I may not have thought of the story line as being in poor taste, but I am, so I did. I didn't think it was realistic that a family that had a close family member who was adopted (in this case, the kids' cousin) would portray adoption as something like a horrible family secret. I also thought about how this would make adopted kids who were watching the show feel. The message was that being adopted was a bad thing.
When I was growing up, my family was always very open about adoption. More than a few times when a friend learned I was adopted they would respond something like this, "Oh my God, my brothers used to tell me that I was adopted! I would bawl my eyes out and my parents had to convince me that I wasn't." I would be speechless. I could only wonder why someone would think that they were relating to me being adopted by sharing that adoption was used as a method of teasing in their family.
As an adult, people amaze me in the same way. When I was out with Mikias, shortly after bringing him home, I was approached by a woman with a girl about 4 years old, the same age that Mikias was. She asked if he was mine "yes", adopted?, "yes". She responded with "Oh my God, I almost had to adopt! We even contacted an adoption agency, but thank God, I got pregnant." It made me feel just like I did when kids would share their adoption as teasing stories...speechless.
Like 'People' magazine, I think our world is catching up to the fact that adoption is just another way to become part of a family. Hopefully Modern Family will resist turning adoption into another punch line and just continue to be the hilarious show that it is.