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.
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.
I think cosplay is a bit of an art form. A lot of time goes into some cosplay, especially the more meticulous, detail oriented costumes. Because of that, it’s more than just “dressing up” to me. I see it no differently than movie costumes or FX makeup in terms of seriousness. Some people even make careers into it. I assume some others are able to break into other careers like acting or the aforementioned FX makeup.
It’s not everyone’s cup of tea… and I respect that. However, there’s a lot more that goes into cosplay than what people see at face value.