This subject has turned into a 12-page saga on another forum I read. They've got people starting letter campaigns to Disney/Marvel to get the line changed.
They've also got a bunch of adoptees/adoptive parents telling them to chill out.
Keep in mind, this subject has apparently offended adoptees in other films, from what I was able to find out after reading more about this:
Tangled
Lilo & Stitch
Despicable Me
ELF
Annie
Angels in the Outfield
Meet the Robertsons
Basically, anything that involves an orphan, an adoption, or any reference to "real parents".
On one hand, I can understand why it would be difficult when a little one who has been through foster care or an adoption simply doesn't understand what was so funny.
But since the line in Avengers is clearly about Loki and Thor's sudden backtracking when he realized he was defending a mass-murderer, and not about all adoptees in the universe, offending all adoptees was not the intent of that line, and it wasn't offensive.
And yes, the whole controversy is silly. I thought it was funniest lines of the movie.
