People about Cosplay...
The only place it should really matter is in competition. Don’t enter a workmanship based contest with something that you bought or commissioned, and don’t take credit for the work of others.
That said, some contests have a category for commissioned or purchased costumes, you would be fine if you entered there.
It’s a way of expressing your love for a particular anime/manga/video game series. You enjoy the world the author created so much that you feel like dressing up as one of the characters. It’s a tribute of sorts.
It’s fun to take a break from your real life and escape into an anime/manga/video game world, even if just for a day at an anime convention. You get to be someone else for a bit.
Great cosplayers draw crowds of convention-goers, get their picture taken by lots of photographers and receive lots of compliments. It’s flattering.
When you walk through a convention and see other cosplayers, there’s a sense of belonging to a community of people with shared interests. People make eye contact, smile when they recognize your character, ask to take pictures and are generally pretty friendly.
Some people really enjoy the process of planning and creating the costume. Making armor, sewing, and building weapons can be a fun and rewarding hobby.
To answer your main questions, No and No. Cosplay is supposed to be about inclusiveness, fun, and showing your love for a character.
That being said, as with any group of people, there will be jerks on both sides. There will be those that make their costumes and look down on those that buy them, and vice versa. Jerks can be found at all levels of cosplay, just like regular society. And just like regular society, you have the choice to ignore the jerks and go your own way.
If you are happy with your cosplay, not competing in a 100% bought cosplay and are having fun, that really is all that matters.
People who make their cosplays receive just as many nasty comments and critiques as those that buy them by the way.