People about Cosplay...
Putting aside for the moment that the tone of the question doesn’t imply the most open of minds, cosplay is – simply – acting. Do you consider Mel Gibson, Ken Branagh, David Tennant, Cumberbatch, et. al. immature for wanting to dress up and act as Hamlet? Cosplay is a similar – if not identical – mindset: people, inspired by characters, possessing the right combination of talent, bravery and self-awareness, performing as said character for an audience. Whether it’s a convention stage or a Broadway stage makes no difference. The person who portrays Deadpool or Master Chief is very much spiritual kin to the person who plays King Lear or Hamlet. It’s wrong to praise one and denigrate the other based on the source of their inspiration, for to declare which works are “great” and which are not is subjective or worse. Still, even if most consider it blasphemy to compare Marvel to Shakespeare, the motivation to portray characters from either realm is identical and the healthy mindset WON’T criticize this, realizing that whatever it doesn’t “get” is not automatically inferior or invalid.
PS: Ironically you will find, if you but ask, that most cosplayers as children were very successful Trick or Treaters, as Halloween is quite often the “bug” that bites them for their subsequent motivation.
It depends on what you mean by popular. It’s more or less exclusive to conventions, which have the benefit of only happening once each year per con. Attendees like myself have time to craft and sew awesome things. I know why I like it-it pushes my creative boundaries and has become my full time hobby and side-job. It’s very fun to be someone else, but it’s also fun to show off your work. I made my husband a great Groot costume for DragonCon last year and it was one of the best weekends ever. We had a blast as ‘Rockette’ and Groot. There’s something about participating in a huge fandom that is just pure fun.
I don’t think it’s really all that popular with the general public, when people don’t know who you are it can be disappointing. They don’t really know what to make of you when you come into a restaurant painted blue with a handful of storm troopers after an event or convention. Kids seem to go nuts over it though, I’m also a member of Rebel Legion and dress as Princess Leia for events. Adults are amused but kids go crazy for Darth Vader. Popularity really only seems to stretch as far as known characters.
Cosplay is used to portray a character, in complete characterization, sometimes even down to speech and acting.
Culture appropriation, in my opinion, is always negative, portraying double standards that favor white people. For example, hairstyles used by black people seem trashy and inappropriate, but in white people they are deemed edgy.
Cosplay is a representation of the love for a character, they are acting as the character, their race or cultural background of said character usually has nothing to do with the character, it is a simple fact about them.
When a person does “cosplay”, by making fun of another race, say they dress up as a black character by simply putting on brown makeup, this is racism.
However, correctly portraying the character who happens to be black, is cosplay and is not appropriating the culture of said character, simply using their image to act as them.